Previous Talks

Online Talks Available

Available online, PuzzleX, Barcelona, Spain, 7 November 2023

Why Grow Meat, Fish, and Tumor Avatars in the Lab?

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Available online, Fireside Chat Series, Terasaki Institute, 8 May 2020

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Available online, ACS Spring 2020 Meeting

Kristopher Barr, Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA 90095

Surface-Mediated Crystal Growth of Aurous Cyanide from Molecular Self-Assembled Monolayers

Self-assembled monolayers have been used to pattern surfaces at the nanometer scale. These patterns enable us to change the surface properties of materials using surface functionalization. Cyanide has a strong affinity towards gold; however, the basic chemical and physical properties of gold cyanide compounds remain largely unexplored. Unraveled by scanning tunneling microscopy, cyanides can form monolayers on gold substrates when exposed to dilute concentrations of cyanide vapor with two distinct absorption geometries: carbon bound to gold and nitrogen bound to gold. Upon prolonged vapor deposition, the self-assembled cyanide monolayers reconfigure into large-scale aurous cyanide (AuCN) crystals. Similar to our previous discoveries on self-assembled monolayers, we found two distinct morphologies. Those monolayers have similar optical properties, but significantly different cyanide vibrational modes. We postulate that the unit cell also rearranges resulting in structures differing in both gold-cyanide orientation and long-range ordering. We anticipate that our findings will lead to new insights for controlled surface-mediated crystal growth.

Available online, iCANX, broadcast from Beijing, China, April 2020

Nanotechnology Approaches to Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Biology functions at the nanoscale. Thus, there are special opportunities not only to make biological measurements using nanotechnology, but also to interact directly in order to influence biological outcomes. Nanoscience and nanotechnology developed from chemistry, physics, biology, engineering, medicine, toxicology, and a host of other fields. Along the way, we taught each other our problems, challenges, and approaches. The interdisciplinary communication skills that were developed and are now part of our training remain unique to the field. As a result, nanoscience contributes to a wide range of other fields, such as neuroscience and the microbiome.

Sunday 14 April 2024, 4 PM, 2033 Young Hall

Alpha Chi Sigma Lecture, UCLA, Los Angeles, CA 90095

From Moving Atoms to Medicine: Exploring the Nanoscale World

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Friday 5 April 2024, 10³⁰ AM, 2101 Engineering V

Materials Science & Engineering Department Seminar, UCLA, Los Angeles, CA 90095

Control of Chirality, Spin, and Orbitals in Semiconductor-Based Chiral Molecular Devices

Tianhan Liu, Department of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095, USA

Chirality-induced spin selectivity (CISS) is a phenomenon in which structural chirality can lead to different conductivities for electrons with opposite spins. This intriguing effect has significant implications on the intricate interplay between structural chirality, electronic spin, and orbitals.

To obtain a comprehensive understanding of CISS and to demonstrate its potential device functionality, we have developed a robust device platform of chiral molecular junctions constructed on epitaxial magnetic and nonmagnetic semiconductors. Our approach involves the fabrication of normal metal/chiral molecules/semiconductor junctions and electrical measurements of the spin-valve effect and Hanle effect. Our results generate critical insights into the underlying physics of CISS and highlight the potential for a novel scheme of semiconductor spintronics free of magnetic materials.

Thursday 4 April 2024, 4222 Young Hall

Chem 218 Exit Seminar, UCLA, Los Angeles, CA 90095

Atomic-Scale Investigations in Two Dimensions: Self-Assembled Monolayers, Twisted Materials, and MXenes

Katherine E. White, Department of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095, USA

Surfaces play important roles in understanding materials’ interactions with their environments. Controlling and understanding the nanoscale properties of these surfaces enables optimizing the design of devices for electronics, photonics, phononics, and more. I will discuss two-dimensional (2D) materials in two different manners. First, I will describe our recent advances in elucidating the interactions underlying the high quality and stability of carborane-based self-assembled monolayers (SAMs). Using these rigid cage molecules enables more pristine SAMs and careful control over intermolecular interactions, specifically dipole-dipole forces. By controlling dipoles, we can elucidate weak intermolecular interactions normally overshadowed by stronger forces. We map individual isomers in mixed monolayers. These carborane SAMs provide avenues for the investigation of dynamics in monolayers, specifically the interplay between substrate- and adsorbate-mediated interactions. Then, I will share our insights into two classes of 2D materials: twisted bilayers and MXenes. By understanding and controlling Moiré patterns in classic 2D materials such as graphene, we enable more effective phonon interactions and therefore more precise control of thermal transport. Finally, MXenes are a novel family of 2D carbides and nitrides that have generated great excitement within the scientific community. Despite this attention, there is a paucity of atomically resolved local electronic and physical insight on MXene surfaces, which would enable optimization of key properties for the many applications for which these materials have been proposed. I will present local structural, spectroscopic, and chemical investigations of Ti 3 C 2 T x MXene towards the goal of energy storage.

Tuesday 19 March 2024, 2⁵⁵ PM, Room 229 – Ernest N. Morial Convention Center, New Orleans, LA

American Chemical Society Meeting, Perspectives on Climate Change Literacy & Education: Local to International, New Orleans, LA, 17-21 March 2024

Scalability of Low-Carbon Hydrogen Production to Achieve the Energy Transition

Erika López Lara, Department of Chemistry & Biochemistry, Los Angeles, CA 90095, USA

Monday 18 March 2024, 10²⁰ AM, Room 244 – Ernest N. Morial Convention Center, New Orleans, LA

American Chemical Society Meeting, Dreyfus Award in Chemical Imaging Symposium, New Orleans, LA, 17-21 March 2024

Nanoscale Chemical Imaging

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

By developing, combining, and applying new modalities of atomic-resolution imaging with scanning probe microscopies and spectroscopies, we have been able to measure structure, function, and spectra simultaneously. By combining these methods with ideas and methods from sparsity, we have been able to acquire statistically significant distributions of data that enable us to resolve and to understand heterogeneous structure, function, and mechanisms of molecules, materials, and assemblies at the nanoscale. This heterogeneity is a key feature that is present even for atomically precise structures. I discuss examples at the ultimate limits of miniaturization of switches and motors, in biomolecular assemblies, and in measuring exposed and buried interactions and motion, all with extraordinary precision. These advances are opening the nanoscale world for understanding and control.

Sunday 17 March 2024, 2⁰⁵ PM, Room 223 – Ernest N. Morial Convention Center, New Orleans, LA

American Chemical Society Meeting, New Orleans, LA, 17-21 March 2024

Measuring and Leveraging Local Structure in Materials for Hydrogen Storage

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We measure the local structure in materials, such as MXenes, that have been proposed for hydrogen storage. The specific interactions at and near vacancies, adsorbates, and defects can vary substantially from the pristine material. By using combinations of scanning probe microscopies and spectroscopies, closely coupled to theory, we are able to determine local electronic and structural effects, as we build a comprehensive picture of how to optimize these materials for hydrogen storage and other chemistries.

Friday 8 March 2024, 2³⁵ PM

Beauty Accelerate Conference, The Millenium Biltmore Hotel, Los Angeles, CA

Inclusive Beauty: Product Design for Deeper Skin Tones

AJ Addae, SULA Labs, Los Angeles, CA 90024, USA and Department of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095, USA

About half of Black Americans feel skin care brands have a long way to go to ensure products work well for people of color, per a 2023 Aveeno poll. Similar dissatisfaction has been witnessed in the multicultural hair care and makeup spaces. This is a dynamic that can be resolved by offering true efficacy to consumers, resulting in market opportunities for brands. This session will center on best practices for addressing the needs of deeper skin-toned consumers in product development. From hair and skin care, to sunscreens and more, this session will provide R&D and their marketing partners with the insights needed to ensure products effectively meet the needs of this massive, dissatisfied consumer base.

Friday 8 March 2024, 1 PM

Geffen Academy, Los Angeles, CA

Nanotechnology Approaches to Biotechnology, Medicine, and Sustainability

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Thursday 7 March 2024, 4 PM, Conference Center, Room M100H

American Physical Society Meeting, Minneapolis, MN, 4-8 March 2024

Square-Root Topological Graphene Nanoribbons Modulated by Electric Field

Haiyue Huang (University of California, Los Angeles), Ioannis Petrides (University of California, Los Angeles), Jeremy Levy (University of Pittsburgh), Paul S. Weiss (University of California, Los Angeles), and Prineha Narang (University of California, Los Angeles)

Graphene nanoribbons (GNRs) have unique edge structures and can be designed to have rich topological behavior. Extensive research has been conducted on nontrivial boundary states in GNRs, showing great potential for applications in carbon-based quantum computing devices. To harness these boundary states, it is desirable to achieve spatial manipulation and to be able to control the corresponding fractional charges. In this study, through first-principles calculations and tight-binding modeling, we present a class of square-root topological GNRs that exhibit enriched nontrivial band structures when subjected to a transverse electric field. A boundary state can be created between regions of different directions of the electric field, which can be experimentally engineered to move, to add, or to delete such a state. As we illustrate with several examples, the fractional charge of the boundary state can be further tuned by strategic inclusion or exclusion of zigzag edge units. These results suggest the potential for realizing spatially controllable, arbitrary fractional charges with GNRs, thereby providing new opportunities and design principles for GNRs in quantum information science.

*This work is supported by Office of Naval Research through Multidisciplinary University Research Initiative (#N00014-20-S-F003).

Tuesday 5 March 2024, 12:06 PM, Conference Center, Room 101B

American Physical Society Meeting, Minneapolis, MN, 4-8 March 2024

Chirality-Induced Magnet-Free Spin Generation in Semiconductors

Yuwaraj Adhikari (Florida State University, Tianhan Liu (University of California, Los Angeles), Hailong Wang (State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China), Yiyang Jiang (Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel), Zhenqi Hua (Florida State University), Haoyang Liu
(Florida State University), Pedro Schlottmann (Florida State University), Hanwei Gao
(Florida State University), Paul S. Weiss (University of California, Los Angeles), Binghai Yan (Weizmann Institute of Science), Jianhua Zhao (Chinese Academy of Sciences), and Peng Xiong (Florida State University)

Efficient interconversion of electronic charge and spin is central to the fundamental research and device applications in spintronics and quantum information. While spin generation in semiconductors is often realized through electrical injection from a ferromagnet, there are notable advantages to exploring nonmagnetic approaches for creating spin polarization. One such approach is via chirality-induced spin selectivity (CISS), where structural chirality induces spin polarization in the direction of the electrical current. In this study, we employ CISS to efficiently generate spin accumulation in n-doped GaAs by electric current injection from a normal metal (Au) electrode through a self-assembled monolayer of chiral molecules (alpha-helix L-polyalanine, AHPA-L). Our previous work has already demonstrated that CISS can yield significant spin valve signals in similar devices with (Ga, Mn)As acting as the spin analyzer^1,2. The resulting spin polarization is detected as a Hanle effect in the n-GaAs, which follows a distinct universal scaling with temperature and bias current. The experiment represents a definitive observation of CISS in a fully nonmagnetic device structure, demonstrating its capacity to generate spin accumulation in a conventional semiconductor. The results provide valuable insights into the physical mechanism of CISS and introduce a novel pathway to magnet-free semiconductor spintronics.

*Work supported by NSF grant DMR-1905843

Tuesday 5 March 2024, 11:30 AM, Conference Center, Room 101B

American Physical Society Meeting, Minneapolis, MN, 4-8 March 2024

Control of Chirality, Spin, and Orbitals in Semiconductor-Based Chiral Molecular Devices

Tianhan Liu (University of California, Los Angeles)

Chirality-induced spin selectivity (CISS) is a phenomenon in which structural chirality can lead to different conductivities for electrons with opposite spins.[1] This intriguing effect has significant implications on the intricate interplay between structural chirality, electronic spin, and orbitals.

To obtain a comprehensive understanding of the underlying physical mechanisms of CISS and to demonstrate its potential device functionality, we have developed a robust device platform of chiral molecular junctions constructed on epitaxial magnetic and nonmagnetic semiconductors. Our approach involves the fabrication of normal metal/chiral molecules/semiconductor junctions and electrical measurements of the spin-valve effect [2,3] and Hanle effect [4]. The device design effectively addresses the issue of electrical shorting, thus enabling a systematic exploration of the physical origins of CISS as follows:

1. Our results provide definitive evidence for both nonlinear- and linear-response components in the bias-current dependences of the CISS spin-valve magnetoconductance;[2]

2. Through direct comparisons of chiral molecular spin valves utilizing Au and Al electrodes, our experiments demonstrate the essential roles of the spin-orbit coupling of the electrodes.[3] The result supports the theory that chiral molecules act as orbital polarizers, rather than spin filters;[5] and

3. CISS-induced Hanle effect is observed in junctions with conventional n-GaAs.[4] The Hanle amplitude displays distinctive scaling behavior with temperature and bias current. It highlights the potential for a novel scheme of semiconductor spintronics free of magnetic materials.

Our experiments have generated critical insights into the underlying physics of CISS and provided guidelines for its practical applications. In addition, our work emphasizes the need for clearer understanding of the key concepts of spin polarization in transport studies of CISS.[6]

*Graphene nanoribbons (GNRs) have unique edge structures and can be designed to have rich topological behavior. Extensive research has been conducted on nontrivial boundary states in GNRs, showing great potential for applications in carbon-based quantum computing devices. To harness these boundary states, it is desirable to achieve spatial manipulation and to be able to control the corresponding fractional charges. In this study, through first-principles calculations and tight-binding modeling, we present a class of square-root topological GNRs that exhibit enriched nontrivial band structures when subjected to a transverse electric field. A boundary state can be created between regions of different directions of the electric field, which can be experimentally engineered to move, to add, or to delete such a state. As we illustrate with several examples, the fractional charge of the boundary state can be further tuned by strategic inclusion or exclusion of zigzag edge units. These results suggest the potential for realizing spatially controllable, arbitrary fractional charges with GNRs, thereby providing new opportunities and design principles for GNRs in quantum information science.

Thursday 8 February 2024, 3:50 PM (local time)

Advancement in Chemical and Biological Research: Breaking Boundaries and Shaping the Future, Tarsadia Institute of Chemical Science, Bardoli, Gujarat, India

Nanotechnology Approaches to Biotechnology, Medicine, and Sustainability

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Biology functions at the nanoscale. Thus, there are special opportunities not only to make biological measurements using nanotechnology, but also to interact directly in order to influence biological outcomes. I describe how we fabricate and use nanostructures to advance high-throughput gene editing for cellular therapies targeting genetic diseases and cancer immunotherapy. We also use microfluidics and functionalized nanostructured features in the selective capture, probing, and release of single circulating tumor cells in liquid biopsies in order to diagnose cancers and to assess the efficacy of treatments. We exploit molecular recognition and phase transitions to create molecular treadmills to grow three-dimensional co-cultured organoids efficiently. We exploit supramolecular assembly, acoustofluidics, specific surface functionalization, and plasmonics to enable these processes. Nanoscience and nanotechnology developed from chemistry, physics, biology, engineering, medicine, toxicology, and a host of other fields. Along the way, we taught each other our problems, challenges, and approaches. The interdisciplinary communication skills that were developed and are now part of our training remain unique to the field. As a result, nanoscience contributes to a wide range of other fields, such as neuroscience, the microbiome, oncology, cellular agriculture, and more.

Wednesday 24 January 2024, 2 PM

2024 International Conference on Superwettability+, LEO 1-4 Resorts World Convention Centre, Level 1, Sentosa, Singapore, 24 – 25 January 2024, Plenary Lecture

Understanding and Controlling Interactions and Properties at Atomically Precise Interfaces

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

One of the key advances in nanoscience and nanotechnology has been our increasing ability to reach the limits of atomically precise structures. By having developed the “eyes” to see, to record spectra, and to measure function at the nanoscale, we have been able to fabricate structures with precision as well as to understand the important and intrinsic heterogeneity of function found in these assemblies. The physical, electronic, mechanical, and chemical connections that materials make to one another and to the outside world are critical. Just as the properties and applications of conventional semiconductor devices depend on these contacts, so do nanomaterials, many nanoscale measurements, and devices of the future. We explore the important roles that these contacts can play in preserving key transport and other properties. Initial nanoscale connections and measurements guide the path to future opportunities and challenges ahead. Band alignment, minimally disruptive connections, and control of spin and heat are all targets and can be characterized in both experiment and theory. I discuss our initial forays into this area in a number of materials systems.

Wednesday 24 January 2024, 11:30 AM

National University of Singapore Innovation Symposium, Singapore, LT 37, MD 1 Tahir Building

Taking on Unsolved Problems in Healthcare Disparities through Nano- and Biotechnologies

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Friday 19 January 2024

UCLA Department of Chemistry & Biochemistry Seaborg Award Symposium Poster Session, CNSI, UCLA, Los Angeles, CA

Atomic-Scale Exploration of Functional Ti₃C₂ MXenes

Katherine A. White, Gilad Gani, Yi Zhu Chu, John C. Thomas, Alexander Weber-Bargoni, Kah-Chun Lau, Yury Gogotsi, and Paul S. Weiss

California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Department of Physics and Astronomy, California State University, Northridge, Northridge, CA, USA

Molecular Foundry, Lawrence Berkeley Laboratory, Berkeley, CA 94720, USA

Department of Materials Science & Engineering, Drexel University, Phiadelphia, PA, USA

MXenes, a new family of 2D materials, have shown promise across a wide range of applications, including as candidates for hydrogen storage. We are examining how terminal groups interact with and modify the chemistry and electronic structure of the surface as well as what happens when these terminal groups undergo selective chemical reactions towards the goal of hydrogen storage. To date, little information is known about defects, adsorption sites, and other structures responsible for the interactions with hydrogen and other materials. We are using spectroscopic imaging with atomic resolution and closely coupled theory to determine the electronic, chemical, and physical properties of these sites in and on Ti₃C₂T_x. Terminal functional groups as well as the small TiO₂ clusters that form upon oxidation are resolved and are being characterized.

Sunday 18 December 2023

IIT Madras, Chennai, Tamil Nadu, India

Translating Nanotechnology Advances in Biotechnology, Medicine, and Sustainability

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Friday 16 December 2023

International Conference on Molecular Matter, Chennai, Tamil Nadu, India, 16-18 December 2023

Advancing Sustainability through Control of Charge, Heat, and Spin at Atomically Precise Interfaces

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Friday 1 December 2023

Institute for Neuro Innovation Research Symposium and Gala, Santa Monica, CA

Taking on Unsolved Problems and Healthcare Disparities

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Tuesday 28 November 2023

University of New South Wales, Australian Centre for NanoMedicine, Sydney, NSW, Australia

Translating Nanotechnology Advances in Biotechnology, Medicine, and Sustainability

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Biology functions at the nanoscale. Thus, there are special opportunities not only to make biological measurements using nanotechnology, but also to interact directly in order to influence biological outcomes. I describe how we fabricate and use nanostructures to advance high-throughput gene editing for cellular therapies targeting genetic diseases and cancer immunotherapy. We also use microfluidics and functionalized nanostructured features in the selective capture, probing, and release of single circulating tumor cells in liquid biopsies in order to diagnose cancers and to assess the efficacy of treatments. We exploit molecular recognition and phase transitions to create molecular treadmills to grow three-dimensional co-cultured organoids efficiently. We exploit supramolecular assembly, acoustofluidics, specific surface functionalization, and plasmonics to enable these processes. Nanoscience and nanotechnology developed from chemistry, physics, biology, engineering, medicine, toxicology, and a host of other fields. Along the way, we taught each other our problems, challenges, and approaches. The interdisciplinary communication skills that were developed and are now part of our training remain unique to the field. As a result, nanoscience contributes to a wide range of other fields, such as neuroscience, the microbiome, oncology, cellular agriculture, and more.

Saturday 18 November 2023

Samsung Science & Technology Foundation Global Research Symposium: Molecules and Materials in Nanoscience and Beyond, Beverly Hills, CA, November 15-18, 2023

Understanding and Controlling Charge, Heat, and Spin at Atomically Precise Interfaces

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

[1] Donhauser Z.J., … Weiss, P.S.* Science. 2001.

[2] Kim J., … Weiss, P.S.* Nano Letters. 2014.

[3] Han P.,* … Weiss, P.S., Asao N.,* Hitosugi, T. ACS Nano. 2015.

[4] Aiello C.L.,* Weiss P.S., … ACS Nano. 2022.

[5] Li M., … Weiss P.S., Hu Y.* Science. 2023.

Sunday 12 November 2023

Institute of Molecular Medicine, Hangzhou, China

Translating Nanotechnology Advances in Biotechnology, Medicine, and Sustainability

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Biology functions at the nanoscale. Thus, there are special opportunities not only to make biological measurements using nanotechnology, but also to interact directly in order to influence biological outcomes. I describe how we fabricate and use nanostructures to advance high-throughput gene editing for cellular therapies targeting genetic diseases and cancer immunotherapy. We also use microfluidics and functionalized nanostructured features in the selective capture, probing, and release of single circulating tumor cells in liquid biopsies in order to diagnose cancers and to assess the efficacy of treatments. We exploit molecular recognition and phase transitions to create molecular treadmills to grow three-dimensional co-cultured organoids efficiently. We exploit supramolecular assembly, acoustofluidics, specific surface functionalization, and plasmonics to enable these processes. Nanoscience and nanotechnology developed from chemistry, physics, biology, engineering, medicine, toxicology, and a host of other fields. Along the way, we taught each other our problems, challenges, and approaches. The interdisciplinary communication skills that were developed and are now part of our training remain unique to the field. As a result, nanoscience contributes to a wide range of other fields, such as neuroscience, the microbiome, oncology, cellular agriculture, and more.

Tuesday 7 November 2023

PuzzleX, Barcelona, Spain

Mysteries of the Brain

Anne M. Andrews, Departments of Psuchiatry & Behavioral Health and Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095, USA

and

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Tuesday 7 November 2023

PuzzleX, Barcelona, Spain

Why Grow Meat, Fish, and Tumor Avatars in the Lab?

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Friday 27 October 2023

Northwestern University, Center for Molecular Quantum Transduction, Evanston, IL

Understanding and Controlling Charge, Heat, and Spin at Atomically Precise Interfaces

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Friday 20 October 2023

Republic of the Philippines, Department of Science and Technology, Philippine Council for Industry, Energy, and Emerging Technology Research and Development (PCIEERD), Manila, The Phillipines (by Zoom)

A Career in Nanoscience So Far: From Fundamental Science to Translational and Commercialization

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Tuesday 10 October 2023, 4:30 PM (6:30 AM Pacific Time)

Second Forum of the Alliance of Entrepreneurial Universities in Africa and the Workshop on STI4SDGs Roadmaps and Actions in Africa, United Nations Conference Center, Addis Ababa, Ethiopia

**Design of ex Vivo Tissue Studies to Elucidate Melanosome and Epidermal Function in Darker Skin Tones**

Ajoa J. Addae, Department of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095, USA

Morphological differences between lighter and darker skin tones are largely informed by the ultraviolet radiation (UVR)-absorptive pigment, melanin. Melanin is most responsible for absorbing UVR, which has been demonstrated to result in photoaging, and melanoma onset. Darker skin contains 3-6 times higher levels of melanin than fairer skin, and possesses larger and more melanosomes compared to fair skin. Three dimensional in vitro and ex vivo skin tissue models that reconstruct human skin often lack the number and size of melanosomes necessary to accurately represent melanin-associated function in darker skin tones, such as enzymatic repair rates of UVR-induced lesions. Furthermore, 3D skin tissue models are increasingly beneficial for epidermal investigations in that they do not require human subjects. This presentation reviews our optimization strategies and data using 3D ex vivo skin tissue models that utilize skin cells collected and cultured from dark skin to evaluate topical skin treatments.

Wednesday 27 September 2023, 9 AM

Flatlands2023, Prague, Czech Republic, 25-29 September 2023

Understanding and Controlling Charge, Heat, and Spin at Atomically Precise Interfaces

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Monday 25 September 2023, 5 PM

Science Salon at the Hotel Fitzgerald, Prague, Czech Republic

From Moving Atoms to Medicine: Exploring and Controlling the Nanoscale World

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Biology functions at the nanoscale. Thus, there are special opportunities not only to make biological measurements using nanotechnology, but also to interact directly in order to influence biological outcomes in treating genetic diseases and cancer, in repairing wounds, and in wellness. Nanoscience and nanotechnology developed from chemistry, physics, biology, engineering, medicine, toxicology, and a host of other fields. Along the way, we taught each other our problems, challenges, and approaches. The communication skills that we developed are now part of our training remain unique to the field. As a result, nanoscience contributes to a wide range of other fields, such as neuroscience and the microbiome.

Friday 22 September 2023

E-Prot Symposium, Alicante, Spain

Understanding and Controlling Charge, Heat, and Spin at Atomically Precise Interfaces

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Thursday 14 September 2023, 3 PM

UCLA Chemical Biology Interface Retreat, Huntington Gardens, Pasadena, CA, 14 September 2023

Reactive Oxygen Species Generation from Zinc Oxide and Titanium Dioxide Particles in Sunscreens and Viability of Skin Microflora

Ajoa J. Addae, Department of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095, USA

Sunscreen plays crucial roles in protecting the skin from the harmful effects of ultraviolet (UV) radiation, which can cause sunburn, premature aging, and increased risks of skin cancer. Commercial sunscreens often contain micron- or nano-sized particles of zinc oxide (ZnO) and titanium dioxide (TiO2) due to their superior UV protection on the skin. These metal oxides have been shown to possess antimicrobial properties, which are attributed to the production of reactive oxygen species (ROS) that disrupt mitochondrial function of skin bacteria. The role of the skin microbiome in UV-induced immune suppression has been well established. However, the interactions between ZnO and TiO2 nanoparticles and bacteria on the surface of the skin microbiome are not well understood. This talk primarily aims to demonstrate current efforts that shed light on metal oxide-induced ROS during UV light attenuation and elucidate the impact of ZnO and TiO2 nanoparticles on the vast skin microbiota in the context of sunscreen usage. Insights from this work will be helpful to attain our ultimate destination of engineering an antioxidant-doped metallic oxide nanoparticle that lessens the extent to which mitochondrial interaction disrupts the viability of skin microbiota.

Wednesday 13 September 2023, 9 AM

2nd International Conference on Nanotechnologies & Bionanoscience (NanoBio), Heraklion, Crete, Greece, 11-15 September 2023

Nanotechnology Approaches to Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Biology functions at the nanoscale. Thus, there are special opportunities not only to make biological measurements using nanotechnology, but also to interact directly in order to influence biological outcomes. I describe how we fabricate and use nanostructures to advance high-throughput gene editing for cellular therapies targeting genetic diseases and cancer immunotherapy. We also use microfluidics and functionalized nanostructured features in the selective capture, probing, and release of single circulating tumor cells in liquid biopsies in order to diagnose cancers and to assess the efficacy of treatments. We exploit molecular recognition and phase transitions to create molecular treadmills to grow three-dimensional co-cultured organoids efficiently. We exploit supramolecular assembly, acoustofluidics, specific surface functionalization, and plasmonics to enable these processes. Nanoscience and nanotechnology developed from chemistry, physics, biology, engineering, medicine, toxicology, and a host of other fields. Along the way, we taught each other our problems, challenges, and approaches. The interdisciplinary communication skills that were developed and are now part of our training remain unique to the field. As a result, nanoscience contributes to a wide range of other fields, such as neuroscience, the microbiome, oncology, cellular agriculture, and more.

Monday 24 August 2023

YUCOMAT 24, Materials Research Society of Serbia, Herceg Novi, Montenegro, Plenary Lecture

Understanding and Controlling Charge, Heat, and Spin at
Atomically Precise Interfaces

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Sunday 27 August 2023, 9:55 AM

ChinaNANO 2023, The 9th International Conference on Nanoscience and Technology, Session 4 Beijing, China, 25 – 28 August 2023

“Spin Polarization” in Transport Studies of Chirality-Induced Spin Selectivity

Tianhan Liu^1,2 and Paul S. Weiss^1,2,3,4

¹California NanoSystems Institute and Departments of ²Chemistry & Biochemistry, ³Bioengineering, and ⁴Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Chirality-induced spin selectivity (CISS) is a recently discovered effect that structural chirality can result in different conductivities for electrons with opposite spins.¹ Spin polarization (SP) describes the fraction of spins generated along the chiral axis of chiral media originating from non-spin-polarized currents. In the CISS community, SP is the most widely used physical quantity to describe the efficiency of spin filtering/polarizing process. Experimentally, the CISS effect has been studied mainly in chiral bioorganic molecules, such as double-stranded DNA and peptides, via photoemission, chemical reactions, and transport measurements.² Many other organic and inorganic chiral systems have also been explored and large SPs have been reported.³

However, the methods of defining, calculating, and analyzing SP have exhibited inconsistencies across various studies, hindering advancements in the field. It is imperative to define and to calculate SP physically to avoid confusion and to enable direct comparisons between experiments. It is also worth identifying the physical quantities that describe the CISS effect across different assemblies rather than focusing exclusively on SP. In this talk, we will briefly relate the relevant history of the use of SP and focus on the discussion of its determination in different contexts, i.e., photoemission and transport measurements. We will propose a more practical and meaningful figure of merit for quantitative analysis in CISS.

Keywords: chirality-induced spin selectivity, spin polarization, transport, spin-valve

Reference

[1] Naaman, R.; Waldeck, D. H. Annu. Rev. Phys. Chem., 2015, 66: 263.

[2] Evers, F.; Aharony, A.; Bar-Gill, N.; Entin-Wohlman, O. et. al., Adv. Mater. 2022, 34: 2106629.

[3] Chiesa, A.; Privitera, A.; Macaluso, E.; Mannini, M. et al., Adv. Mater. 2023: 2300472.

Saturday 26 August 2023

ChinaNANO 2023, The 9th International Conference on Nanoscience and Technology, Beijing, China, 25 – 28 August 2023, Session 13 Keynote Lecture

Nanotechnology Approaches to Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Biology functions at the nanoscale. Thus, there are special opportunities not only to make biological measurements using nanotechnology, but also to interact directly in order to influence biological outcomes. I describe how we fabricate and use nanostructures to advance high-throughput gene editing for cellular therapies targeting genetic diseases and cancer immunotherapy. We also use microfluidics and functionalized nanostructured features in the selective capture, probing, and release of single circulating tumor cells in liquid biopsies in order to diagnose cancers and to assess the efficacy of treatments. We exploit molecular recognition and phase transitions to create molecular treadmills to grow three-dimensional co-cultured organoids efficiently. We exploit supramolecular assembly, acoustofluidics, specific surface functionalization, and plasmonics to enable these processes. Nanoscience and nanotechnology developed from chemistry, physics, biology, engineering, medicine, toxicology, and a host of other fields. Along the way, we taught each other our problems, challenges, and approaches. The interdisciplinary communication skills that were developed and are now part of our training remain unique to the field. As a result, nanoscience contributes to a wide range of other fields, such as neuroscience, the microbiome, oncology, cellular agriculture, and more.

Friday 25 August 2023

NanoCenter Directors’ Forum, Beijing, China

California NanoSystems Institute and the Challenge Initiative at UCLA

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Thursday 24 August 2023

Nano Energy Lecture, Beijing Institute of Nanoenergy and Nanosystems

Understanding and Controlling Charge, Heat, and Spin at
Atomically Precise Interfaces

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Thursday 17 August 2023, 1 PM, 5101 Engineering V, UCLA, Los Angeles, CA

PhD Thesis Defense: Nanocellulose Biomaterial for Skeletal Muscle Tissue Engineering and Surgical Mesh Development

Melina Mastrodimos, Department of Bioengineering, UCLA, Los Angeles, CA 90095, USA

Monday 14 August 2023, 9:30 AM, 308 Moscone Center South

American Chemical Society National Meeting, 13 – 18 August 2023, San Francisco, CA

Controlling Nanoscale Materials Function and Chemistry for Human Health

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Biology functions at the nanoscale. Thus, there are special opportunities not only to make biological measurements using nanotechnology and chemical control, but also to interact directly in order to influence biological outcomes. I describe how we design chemical interactions and phase transitions to enhance organoid growth for both healthy tissue and to generate avatars of diseased tissue for personalized medicine. Further, in fabricating materials as bioadhesives, we control the availability of chemical functionality for reaction and the mechanical properties of the materials as a function of temperature to suit medical needs.

Sunday 30 July 2023

Gordon Research Conference on Electron Spin Interactions with Chiral Molecules and Materials: Chiral Spin Filtering and its Manifestations from Molecules to Devices, Manchester, NH, 30 July – 3 August 2023

Introduction: Materials, Molecules, and Methods to Understand the Effects of Chirality in Spin Selectivity and Transport

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Friday 21 July 2023, 5 PM

8th International Conference on Chemical Bonding, Kauai, HI, 20-24 July 2023

Understanding and Controlling Charge, Heat, and Spin at Atomically Precise Interfaces

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Monday 17 July 2023, 9 AM

Physics 2023, 2nd International Conference on Physics and its Applications, United Scientific Group, Los Angeles, CA, 17-20 July 2022

Understanding and Controlling Charge, Heat, and Spin at Atomically Precise Interfaces

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Friday 21 April 2023

University of Connecticut, Distinguished Lecture in Materials Science, Storrs, Connecticut

Understanding Charge, Heat, and Spin at Atomically Precise Interfaces

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Tuesday 13 December 2022

Africa MRS 2022, the 11th International Conference for African Materials Research Society, Dakar, Senegal, 12-15 December 2022

Nanotechnology Approaches to Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Wednesday 19 October 2022, Southeast Regional Meeting of the American Chemical Society (SERMAC), San Juan, Puerto Rico, Wednesday 19 – Saturday 22 October 2022

Nanotechnology Approaches to Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Biology functions at the nanoscale. Thus, there are special opportunities not only to make biological measurements using nanotechnology, but also to interact directly in order to influence biological outcomes. I describe how we fabricate and use nanostructures to advance high-throughput gene editing for cellular therapies targeting genetic diseases and cancer immunotherapy. We also use microfluidics and functionalized nanostructured features in the selective capture, probing, and release of single circulating tumor cells in liquid biopsies in order to diagnose cancers and to assess the efficacy of treatments. We exploit supramolecular assembly, acoustofluidics, specific surface functionalization, and plasmonics to enable these processes. Nanoscience and nanotechnology developed from chemistry, physics, biology, engineering, medicine, toxicology, and a host of other fields. Along the way, we taught each other our problems, challenges, and approaches. The interdisciplinary communication skills that were developed and are now part of our training remain unique to the field. As a result, nanoscience contributes to a wide range of other fields, such as neuroscience and the microbiome.

Monday 18 July 2022

Physics 2022, 1st International Conference on Physics and its Applications, United Scientific Group, San Francisco, CA, 18-20 July 2022

Atomically Precise Chemical, Physical, Electronic, and Spin Contacts and Interfaces

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

One of the key advances in nanoscience and nanotechnology has been our increasing ability to reach the limits of atomically precise structures. By having developed the “eyes” to see, to record spectra, and to measure function at the nanoscale, we have been able to fabricate structures with precision as well as to understand the important and intrinsic heterogeneity of function found in these assemblies. The physical, electronic, mechanical, and chemical connections that materials make to one another and to the outside world are critical. Just as the properties and applications of conventional semiconductor devices depend on these contacts, so do nanomaterials, many nanoscale measurements, and devices of the future. We discuss the important roles that these contacts can play in preserving key transport and other properties. Initial nanoscale connections and measurements guide the path to future opportunities and challenges ahead. Band alignment and minimally disruptive connections are both targets and can be characterized in both experiment and theory. I discuss our initial forays into this area in a number of materials systems.

Wednesday 8 June 2022

NanoCanada International Conference 2022: From Earth to Space, Edmonton, Alberta, Canada, 8-10 June 2022

Nanotechnology Approaches to Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Biology functions at the nanoscale. Thus, there are special opportunities not only to make biological measurements using nanotechnology, but also to interact directly in order to influence biological outcomes. Nanoscience and nanotechnology developed from chemistry, physics, biology, engineering, medicine, toxicology, and a host of other fields. Along the way, we taught each other our problems, challenges, and approaches. The interdisciplinary communication skills that were developed and are now part of our training remain unique to the field. As a result, nanoscience contributes to a wide range of other fields, such as neuroscience and the microbiome.

Thursday 2 June 2022

iNano 2022, The 20th Anniversary Celebration, Aarhus University, Aarhus, Denmark, 1-3 June 2022

Nanotechnology Approaches to Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Biology functions at the nanoscale. Thus, there are special opportunities not only to make biological measurements using nanotechnology, but also to interact directly in order to influence biological outcomes. I describe how we fabricate and use nanostructures to advance high-throughput gene editing for cellular therapies targeting genetic diseases and cancer immunotherapy. We also use microfluidics and functionalized nanostructured features in the selective capture, probing, and release of single circulating tumor cells in liquid biopsies in order to diagnose cancers and to assess the efficacy of treatments. We exploit supramolecular assembly, acoustofluidics, specific surface functionalization, and plasmonics to enable these processes. Nanoscience and nanotechnology developed from chemistry, physics, biology, engineering, medicine, toxicology, and a host of other fields. Along the way, we taught each other our problems, challenges, and approaches. The interdisciplinary communication skills that were developed and are now part of our training remain unique to the field. As a result, nanoscience contributes to a wide range of other fields, such as neuroscience and the microbiome.

Monday 16 May 2022

Weizmann Institute of Science, School of Chemistry, Gerhard Schmidt Lecture, Rehovot, Israel

Atomically Precise Chemical, Physical, Electronic, and Spin Contacts

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

One of the key advances in nanoscience and nanotechnology has been our increasing ability to reach the limits of atomically precise structures. By having developed the “eyes” to see, to record spectra, and to measure function at the nanoscale, we have been able to fabricate structures with precision as well as to understand the important and intrinsic heterogeneity of function found in these assemblies. The physical, electronic, mechanical, and chemical connections that materials make to one another and to the outside world are critical. Just as the properties and applications of conventional semiconductor devices depend on these contacts, so do nanomaterials, many nanoscale measurements, and devices of the future. We discuss the important roles that these contacts can play in preserving key transport and other properties. Initial nanoscale connections and measurements guide the path to future opportunities and challenges ahead. Band alignment and minimally disruptive connections are both targets and can be characterized in both experiment and theory. I discuss our initial forays into this area in a number of materials systems.

Thursday 12 May 2022

Baekeland Awards, Fairleigh Dickinson University, Teaneck, New Jersey

Plasmonic Approaches to Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering

Wednesday 11 May 2022 6 AM, CISS Seminar, online

Hanle Effect in Semiconductor-Based Two-Terminal Molecular Junctions

Tianhan Liu, Paul S. Weiss Group, Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

In this talk, I will focus on the experimental studies in semiconductor and molecular spintronics during my PhD. I will first briefly describe spin transport in a persistent photoconductor Si-doped Al0.3Ga0.7As, where we produced the first results of spin lifetimes at various carrier densities on one and the same device. I will then talk about molecular patterning and directed self-assembly of Au nanoparticles on GaAs. Combining the expertise from these two projects, I will focus on the spin-valve and Hanle effect via chirality-induced spin selectivity (CISS) in hybrid semiconductor/molecular devices. We obtained definitive evidence of spin-selective electron transport in two-terminal vertical junctions of (Ga,Mn)As/AHPA-L molecules/Au. The use of the ferromagnetic semiconductor (GA,Mn)As resulted in the realization of a pronounced and stable CISS-induced spin-valve effect, which facilitated a comprehensive and rigorous study of its bias dependences. We also observed the Hanle effect and possible dynamic nuclear polarization in teh junctions of n-GaAs/AHPA-L molecules/Au, which are free of any magnetic material. Our results have practical implication in electrically creating and possibly detecting spin polarized current in semiconductors without using any magnetic material. Finally, I will talk about the ongoing projects on CISS and collaborations at UCLA.

Friday 6 May 2022 12 PM

Arizona State University, Hybrid In-Person & Zoom – Email for Zoom link (tianhanliu@g.ucla.edu)

Spin Transport in Semiconductor Heterostructures, Hybrid Nanostructures and Beyond

Tianhan Liu, Paul S. Weiss Group, Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

Wednesday 4 May 2022

Texas Center for Superconductivity, University of Houston, Houston, Texas

Atomically Precise Chemical, Physical, Electronic, and Spin Contacts

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

One of the key advances in nanoscience and nanotechnology has been our increasing ability to reach the limits of atomically precise structures. By having developed the “eyes” to see, to record spectra, and to measure function at the nanoscale, we have been able to fabricate structures with precision as well as to understand the important and intrinsic heterogeneity of function found in these assemblies. The physical, electronic, mechanical, and chemical connections that materials make to one another and to the outside world are critical. Just as the properties and applications of conventional semiconductor devices depend on these contacts, so do nanomaterials, many nanoscale measurements, and devices of the future. We discuss the important roles that these contacts can play in preserving key transport and other properties. Initial nanoscale connections and measurements guide the path to future opportunities and challenges ahead. Band alignment and minimally disruptive connections are both targets and can be characterized in both experiment and theory. I discuss our initial forays into this area in a number of materials systems.

Tuesday 3 May 2022

Rice University, Department of Chemistry, Franklin Memorial Lectures, Houston, Texas.

Nanotechnology Approaches to Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Biology functions at the nanoscale. Thus, there are special opportunities not only to make biological measurements using nanotechnology, but also to interact directly in order to influence biological outcomes. I describe how we fabricate and use nanostructures to advance high-throughput gene editing for cellular therapies targeting genetic diseases and cancer immunotherapy. We also use microfluidics and functionalized nanostructured features in the selective capture, probing, and release of single circulating tumor cells in liquid biopsies in order to diagnose cancers and to assess the efficacy of treatments. We exploit supramolecular assembly, acoustofluidics, specific surface functionalization, and plasmonics to enable these processes. Nanoscience and nanotechnology developed from chemistry, physics, biology, engineering, medicine, toxicology, and a host of other fields. Along the way, we taught each other our problems, challenges, and approaches. The interdisciplinary communication skills that were developed and are now part of our training remain unique to the field. As a result, nanoscience contributes to a wide range of other fields, such as neuroscience and the microbiome.

Thursday 31 March 2022, 12 PM

UCLA Department of Chemistry & Biochemistry, Chem 218 Exit Seminar, UCLA Young Hall 2033 & Zoom

Surface Functionalization, Patterning, and in Situ Growth of Gold Nanoparticles

Gail Vinnacombe-Wilson, Materials Chemistry PhD Candidate, Professor Paul S. Weiss & Professor Steven J. Jonas Groups, University of California, UCLA, Los Angeles, CA 90095

We develop straightforward bottom-up methods for rationally incorporating gold nanoparticles (AuNPs) onto oxide materials, onto polymers, and within microfluidic devices. Plasmonic AuNPs strongly interact with light due to the localized surface plasmon resonance (LSPR) phenomenon. The position and quality of the LSPR peaks depend on the AuNP crystal structure, diameter, geometry, and local dielectric environment, which are easily modulated via wet-chemical synthesis. Beyond high optical extinction, the LSPR effect can also lead to efficient light-to-heat conversion, hot carrier generation and intense localized electric fields. Moreover, when the individual particles are arranged into ordered arrays, even more complex optical responses or high-quality lattice plasmon resonances can be selected. Although wet-chemical synthesis yields individual plasmonic building blocks with superior qualities, precisely engineering plasmonic substrates from colloidal AuNPs is often challenging. The fabrication strategies developed herein have led to advances regarding in situ control over AuNP size and shape, pattern scalability, translatability, and versatility. We employ self-assembly and scalable subtractive soft lithography to produce arbitrary patterns from pre-synthesized AuNPs. In addition, we establish wet-chemical approaches for direct nucleation, growth, and shape-control that avoid time-consuming ligand exchange, self-assembly, and the need for costly equipment. Lastly, we explored in situ shape control to integrate thermoplasmonic gold nanostars within microfluidic platforms to target biomedical applications, including liquid biopsies. Overall, this work has potential impact for the fabrication of plasmonic biomedical devices, sensors, optoelectronics, and heterogeneous catalysts.

Monday 21 March 2022, 5:15 – 5:45 PM (PST)

ACS Spring 2022, San Diego Convention Center, San Diego, CA, Room 22 – San Diego Convention Center

Nanotechnology Approaches to Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Biology functions at the nanoscale. Thus, there are special opportunities not only to make biological measurements using
nanotechnology, but also to interact directly in order to influence biological outcomes. Nanoscience and nanotechnology developed from chemistry, physics, biology, engineering, medicine, toxicology, and a host of other fields. Along the way, we taught each other our problems, challenges, and approaches. The interdisciplinary communication skills that were developed and are now part of our training remain unique to the field. As a result, nanoscience contributes to a wide range of other fields, such as neuroscience and the microbiome.

Sunday 20 March 2022, 12 PM – 1 PM (PST)

ACS Spring 2022, San Diego Convention Center, San Diego, CA, Room 20BCD Theater 5 – San Diego Convention Center

Plasmonic Substrates Through Surface Chemical Patterning and Direct Bottom-Up Synthesis of Gold Nanoparticles

Gail Vinnacombe-Wilson, Materials Chemistry PhD Candidate, Professor Paul S. Weiss & Professor Steven J. Jonas Groups, University of Califonia, Los Angeles

We develop straightforward bottom-up methods for rationally incorporating gold nanoparticles (AuNPs) onto oxide materials, onto polymers, and within microfluidic devices. Plasmonic AuNPs strongly interact with ultraviolet-visible-near infrared light due to the localized surface plasmon resonance (LSPR) phenomenon. The position and quality of the LSPR peaks depend on the AuNP crystal structure, diameter, geometry, and local dielectric environment, which are easily modulated via wet-chemical synthesis. Beyond high optical extinction, the LSPR effect can also lead to efficient light-to-heat conversion, hot carrier generation and intense localized electric fields. Moreover, when the individual particles are arranged into ordered arrays, even more complex optical responses or high-quality lattice plasmon resonances can be selected. Although wet-chemical synthesis yields individual plasmonic building blocks with superior qualities, precisely engineering plasmonic substrates from colloidal AuNPs is often challenging. The fabrication strategies developed herein have led to advances regarding in situ control over AuNP size and shape, pattern scalability, translatability, and versatility. We employ self-assembly and scalable subtractive soft lithography to produce arbitrary patterns from pre synthesized AuNPs. In addition, we establish wet-chemical approaches for direct nucleation, growth, and shape-control that avoid time-consuming ligand exchange, self-assembly, and the need for costly equipment. Lastly, we explored in situ shape control to integrate thermoplasmonic gold nanostars within microfluidic platforms to target biomedical applications, including liquid biopsies. Overall, this work has potential impact for the fabrication of plasmonic biomedical devices, sensors, optoelectronics, and heterogeneous catalysts.

Thursday 17 March 2022

Arizona State University, School of Molecular Science, Eyring Lectures, Public Lecture, Tempe, AZ

Nanotechnology Approaches to Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Biology functions at the nanoscale. Thus, there are special opportunities not only to make biological measurements using
nanotechnology, but also to interact directly in order to influence biological outcomes. Nanoscience and nanotechnology developed from chemistry, physics, biology, engineering, medicine, toxicology, and a host of other fields. Along the way, we taught each other our problems, challenges, and approaches. The interdisciplinary communication skills that were developed and are now part of our training remain unique to the field. As a result, nanoscience contributes to a wide range of other fields, such as neuroscience and the microbiome.

Friday 18 March 2022

Arizona State University, School of Molecular Science, Eyring Lectures, Department Lecture, Tempe, AZ

Atomically Precise Chemical, Physical, Electronic, and Spin Contacts

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Two seemingly conflicting trends in nanoscience and nanotechnology are our increasing ability to reach the limits of atomically precise structures and our growing understanding of the importance of heterogeneity in the structure and function of molecules and nanoscale assemblies. By having developed the “eyes” to see, to record spectra, and to measure function at the nanoscale, we have been able to fabricate structures with precision as well as to understand the important and intrinsic heterogeneity of function found in these assemblies. The physical, electronic, mechanical, and chemical connections that materials make to one another and to the outside world are critical. Just as the properties and applications of conventional semiconductor devices depend on these contacts, so do nanomaterials, many nanoscale measurements, and devices of the future. We discuss the important roles that these contacts can play in preserving key transport and other properties. Initial nanoscale connections and measurements guide the path to future opportunities and challenges ahead. Band alignment and minimally disruptive connections are both targets and can be characterized in both experiment and theory. I discuss our initial forays into this area in a number of materials systems.

Monday 28 February 2022, 11:15 AM – 12 PM

2022 TMS Annual Meeting & Exhibition, Symposium on Plasmonic Nanomaterials, The Minerals, Metals & Materials Society (TMS 2022), Anaheim, California

Plasmonic Approaches to Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Wednesday 23 February 2022, 8:15 PM – 8:50 PM (PST)

APA Nanoforum 2022 International e-Conference on Nanomaterials & Nanoengineering, Asian Polymer Association

Atomically Precise Chemical, Physical, Electronic, and Spin Contracts

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Friday 11 February 2022, 2:00 PM – 2:45 PM (PST)

UCLA Bioengineering Research Day, Graduate Student Speakers, Hossein Montazerian

Sunday 6 February 2022, 11:50 AM – 12:30 PM (PST)

The 6th QU Engineering in Medicine Workshop, Qatar University

Nanotechnology Approaches to Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Biology functions at the nanoscale. Thus, there are special opportunities not only to make biological measurements using nanotechnology, but also to interact directly in order to influence biological outcomes. Nanoscience and nanotechnology developed from chemistry, physics, biology, engineering, medicine, toxicology, and a host of other fields. Along the way, we taught each other our problems, challenges, and approaches. The interdisciplinary communication skills that were developed and are now part of our training remain unique to the field. As a result, nanoscience contributes to a wide range of other fields, such as neuroscience and the microbiome.

Thursday 3 February 2022, 11 AM – 12 PM (PST)

MIT Spring Seminar Lectures

Nanotechnology Approaches to Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Biology functions at the nanoscale. Thus, there are special opportunities not only to make biological measurements using nanotechnology, but also to interact directly in order to influence biological outcomes. I describe how we fabricate and use nanostructures to advance high-throughput gene editing for cellular therapies targeting genetic diseases and cancer immunotherapy. We also use microfluidics and functionalized nanostructured features in the selective capture, probing, and release of single circulating tumoor cells in liquid biopsies in order to diagnose cancers and to assess the efficacy of treatments. We exploit supramolecular assembly, acoustofluidics, specific surface functionalization, and plasmonics to enable these processes. Nanoscience and nanotechnology developed from chemistry, physics, biology, engineering, medicine, toxicology, and a host of other fields. Along the way, we taught each other our problems, challenges, and approaches. The interdisciplinary communication skills that were developed and are now part of our training remain unique to the field. As a result, nanoscience contributes to a wide range of other fields, such as neuroscience and the microbiome.

Wednesday 15 December 2021, 2:00 PM – 2:40 PM (PST)

IEEE NMDC 2021, The 16th IEEE Nanotechnology Materials and Devices Conference, Vancouver, Canada

Atomically Precise Chemical, Physical, Electronic, and Spin Contacts and Interfaces

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

One key trend in nanotechnology is our increasing ability to reach the limits of atonically precise structures. By developing the “eyes” to see, to record spectra, and to measure function at the nanoscale, we are able to fabricate structures with precision. The physical, electronic, mechanical, and chemical connections that materials make to one another are critical. Just as the properties and applications of conventional semiconductor devices depend on these contacts, so do nanomaterials, many nanoscale measurements, and devices of the future. We discuss the important roles that these contacts can play in preserving key transport and other properties.

Pacifichem 2021, Honolulu, Hawaii, 16 – 21 December 2021.

Nanotechnology Approaches to Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Biology functions at the nanoscale. Thus, there are special opportunities not only to make biological measurements using nanotechnology, but also to interact directly in order to influence biological outcomes. Nanoscience and nanotechnology developed from chemistry, physics, biology, engineering, medicine, toxicology, and a host of other fields. Along the way, we taught each other our problems, challenges, and approaches. The interdisciplinary communication skills that were developed and are now part of our training remain unique to the field. As a result, nanoscience contributes to a wide range of other fields, such as neuroscience and the microbiome.

Pacifichem 2021, Honolulu, Hawaii, 16 – 21 December 2021.

Adding the Chemical Dimension to Lithography: Enabling Capture and Sensing of Signaling Molecules, Exosomes, and Cells

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

By controlling the exposed chemical functionality of materials from the submolecular through the centimeter scales, we have enabled new capabilities in biology, medicine, and other areas. I will discuss current and upcoming advances and will pose the challenges that lie ahead in creating, developing, and applying new tools using these capabilities. These advances include using biomolecular recognition in sensor arrays to probe dynamic chemistry in the brain and microbiome systems. We also use these and other nanofabrication strategies to develop new tools to catch and to release exosomes and circulating tumor cells for medical diagnostics.

Monday 6 December 2021, 11:00 AM – 12:00 PM (Japan Time), Sunday 5 December 2021, 7:00 – 8:00 PM (PST)

RIES International Symposium, Online, Sapporo, Hokkaido, Japan, 6 – 7 December 2021.

Atomically Precise Chemical, Physical, Electronic, and Spin Contacts and Interfaces

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Two seemingly conflicting trends in nanoscience and nanotechnology are our increasing ability to reach the limits of atomically precise structures and our growing understanding of the importance of heterogeneity in the structure and function of molecules and nanoscale assemblies. By having developed the “eyes” to see, to record spectra, and to measure function at the nanoscale, we have been able to fabricate structures with precision as well as to understand the important and intrinsic heterogeneity of function found in these assemblies. The physical, electronic, mechanical, and chemical connections that materials make to one another and to the outside world are critical. Just as the properties and applications of conventional semiconductor devices depend on these contacts, so do nanomaterials, many nanoscale measurements, and devices of the future. We discuss the important roles that these contacts can play in preserving key transport and other properties. Initial nanoscale connections and measurements guide the path to future opportunities and challenges ahead. Band alignment and minimally disruptive connections are both targets and can be characterized in both experiment and theory. Chiral assemblies can control the spin properties and thus transport at interfaces. I discuss our initial forays into these areas in a number of materials systems.

Monday 15 November 2021, 5:00 PM (Singapore Time)

A*STAR Editors’ Colloquium Online, Singapore.

Publishing and ACS Nano

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Wednesday 3 November 2021

Departments of Chemistry & Physics, Iowa State University, Ames, Iowa

Atomically Precise Chemical, Physical, Electronic, and Spin Contacts

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

I will discuss the challenges, opportunities, and consequences of pursuing strategies to address both precision on the one hand and heterogeneity on the other. In our laboratories, we are taking the first steps to exploit precise assembly to optimize properties such as perfect electronic contacts in materials. We are also developing the means to make tens to hundreds of thousands of independent multimodal nanoscale measurements in order to understand the variations in structure and function that have previously been inaccessible in both synthetic and biological systems.

Saturday 16 October 2021, 9:30 AM Beijing Time/Friday 15 October 2021, 6:30 PM Pacific Time

International Forum on Microscopy (IFM2021), Guilin, China, Saturday 16 – Sunday 17 October 2021

Imaging Atomically Precise Chemical, Physical, Electronic, and Spin Interfaces

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

It has become possible to fabricate atomically precise structures and interfaces. The key to leveraging this capability is to understand the interfacial properties, such as transport, so as to enable optimization in a targeted and reproducible way.1 Ultimately, we would like to be able to predict the structures formed and their properties. I describe a series of advances in atomic-resolution spectroscopic imaging that have moved us closer to this goal. We are able to measure molecular orbitals across interfaces and the conductance of buried contacts.2,3 We are also able to measure buried interactions in molecular layers.4

This latter property has enabled us to measure the atomically resolved structures of biomolecules without averaging.5,6 In all of the above experiments, we exploit sparsity to record and to analyze information-rich data sets. With statistically significant data sets, we are able to understand heterogeneity in structure and function of complex assemblies.

[1] Han P, Akagi K, Canova FF, Shimizu R, Oguchi H, Shiraki S, Weiss PS, Asao N, Hitosugi T. 2015. Self-assembly strategy for fabricating connected graphene nanoribbons. ACS Nano. 9:12035-12044.

[2] Moore AM, Mantooth BA, Donhauser ZJ, Yao Y, Tour JM, Weiss, PS. 2007. Real-time measurements of conductance switching and motion of oligo(phenylene-ethynylene)s. Journal of the American Chemical Society 129:10352-10353.

[3] Moore AM, Yeganeh S, Yao Y, Claridge SA, Tour JM, Ratner MA, Weiss PS. 2010. Polarizabilities of adsorbed and assembled molecules: Measuring the conductance through buried contacts. ACS Nano 4:7630-7636 (2010).

[4] Thomas JC, Goronzy DP, Dragomiretskiy K, Zosso D, Gilles J, Osher SJ, Bertozzi AL, Weiss PS. 2016. Mapping buried hydrogen-bonding networks. ACS Nano. 10:5446-5451.

[5] Claridge SA, Thomas JC, Silverman MA, Schwartz JJ, Yang Y, Wang C, and Weiss PS. 2013. Differentiating amino acid residues and side chain orientations in peptides using scanning tunneling microscopy. Journal of the American Chemical Society. 135:18528-18535.

[6] Yugay D, Goronzy DP, Kawakami LM, Claridge SA, Song TB, Yan Z, Xie YH, Gilles J, Yang Y, Weiss PS. 2016. Copper ion binding site in β-amyloid peptide. Nano Letters. 16:6282-6289.

10th Vacuum and Surface Sciences Conference of Asia and Australia (VASSCAA-10), Online, Chinese Vacuum Society (CVS), Shanghai, China, 11-14 October 2021.

Atomically Precise Chemical, Physical, Electronic, and Spin Contacts

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Keywords: contacts, interfaces, materials, electronic properties, spin

It has become possible to fabricate atomically precise structures and interfaces. The key to leveraging this capability is to understand the interfacial properties, such as transport, so as to enable optimization in a targeted and reproducible way.1 Ultimately, we would like to be able to predict the structures formed and their properties. I describe a series of advances in atomic-resolution spectroscopic imaging that have moved us closer to this goal. We are able to measure molecular orbitals across interfaces and the conductance of buried contacts.2,3 We are also able to measure buried interactions in molecular layers.4

[1] Han P, Akagi K, Canova FF, Shimizu R, Oguchi H, Shiraki S, Weiss PS, Asao N, Hitosugi T. 2015. Self-assembly strategy for fabricating
connected graphene nanoribbons. ACS Nano. 9:12035-12044.

[3] Moore AM, Yeganeh S, Yao Y, Claridge SA, Tour JM, Ratner MA, Weiss PS. 2010. Polarizabilities of adsorbed and assembled molecules:
Measuring the conductance through buried contacts. ACS Nano 4:7630-7636 (2010).

[4] Thomas JC, Goronzy DP, Dragomiretskiy K, Zosso D, Gilles J, Osher SJ, Bertozzi AL, Weiss PS. 2016. Mapping buried hydrogen-bonding networks. ACS Nano. 10:5446-5451.

Thursday October 7 2021, 6:10 – 7:00 PM (PST)

International Conference on Precision Nanomedicine in Theranostics & The 2021 Annual Meeting of Taiwan Nanomedicine Society (TNS), Tainan, Taiwan, 8-9 October 2021.

Nanotechnology Approaches to Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

2nd KAIST Emerging Materials e-Symposium, Daejeon, South Korea, 4-8 October 2021.

Atomically Precise Chemical, Physical, Electronic, and Spin Contacts

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

27th CRSI National Symposium in Chemistry (NSC-28), Hybrid Meeting, IISER Kolkata, 26-30 September 2021.

Atomically Precise Chemical, Physical, Electronic, and Spin Contacts

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Sunday August 29 2021, 5:00 – 8:00 PM (PST), Monday August 30 2021, 9:00 AM – 12:00 PM (Beijing)

International Conference on Advanced Materials for Energy and Information Technology (AMEIT 2021, Online conference), China, 30-31 August 2021.

Atomically Precise Chemical, Physical, Electronic, and Spin Contacts and Interfaces

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Two seemingly conflicting trends in nanoscience and nanotechnology are our increasing ability to reach the limits of atomically precise structures and our growing understanding of the importance of heterogeneity in the structure and function of molecules and nanoscale assemblies. By having developed the “eyes” to see, to record spectra, and to measure function at the nanoscale, we have been able to fabricate
structures with precision as well as to understand the important and intrinsic heterogeneity of function found in these assemblies. The physical, electronic, mechanical, and chemical connections that materials make to one another and to the outside world are critical. Just as the properties and applications of conventional semiconductor devices depend on these contacts, so do nanomaterials, many nanoscale
measurements, and devices of the future. We discuss the important roles that these contacts can play in preserving key transport and other properties. Initial nanoscale connections and measurements guide the path to future opportunities and challenges ahead. Band alignment and minimally disruptive connections are both targets and can be characterized in both experiment and theory. Chiral assemblies can control the spin properties and thus transport at interfaces. I discuss our initial forays into these areas in a number of materials systems.

Wednesday 25 August 2021, 8:30-9 AM Beijing Time

18th The International Symposium on Electroanalytical Chemistry (ISEAC), Changchun Institute of Applied Chemistry, Changchun, Jilin, China, 24-27 August 2021

Atomically Precise Chemical, Physical, Electronic, and Spin Contacts

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Two seemingly conflicting trends in nanoscience and nanotechnology are our increasing ability to reach the limits of atomically precise structures and our growing understanding of the importance of heterogeneity in the structure and function of molecules and nanoscale assemblies. By having developed the “eyes” to see, to record spectra, and to measure function at the nanoscale, we have been able to fabricate structures with precision as well as to understand the important and intrinsic heterogeneity of function found in these assemblies. The physical, electronic, mechanical, and chemical connections that materials make to one another and to the outside world are critical and are intertwined in terms of their function. Just as the properties and applications of conventional semiconductor devices depend on these contacts, so do nanomaterials, many nanoscale measurements, and devices of the future. We discuss the important roles that these contacts can play in preserving key transport and other properties. Initial nanoscale connections and measurements guide the path to future opportunities and challenges ahead. Band alignment and minimally disruptive connections are both targets and can be characterized in both experiment and theory [1,2]. Chiral assemblies can control the spin properties and thus transport at interfaces [3,4]. I discuss our initial forays into these areas in a number of materials systems.

Sunday August 22 2021, 11:00 AM – 11:30 AM (EST)

ACS Fall 2021 Resilience of Chemistry (In-Person & Virtual), Georgia World Congress Center (GWCC), Atlanta, Georgia

Atomically Precise Chemical, Physical, Electronic, and Spin Contacts in Materials

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Two seemingly conflicting trends in nanoscience and nanotechnology are our increasing ability to reach the limits of atomically precise structures and our growing understanding of the importance of heterogeneity in the structure and function of molecules and nanoscale assemblies. By having developed the “eyes” to see, to record spectra, and to measure function at the nanoscale, we have been able to fabricate structures with precision as well as to understand the important and intrinsic heterogeneity of function found in these assemblies. The physical, electronic, mechanical, and chemical connections that materials make to one another and to the outside world are critical and are intertwined in terms of their function. Just as the properties and applications of conventional semiconductor devices depend on these contacts, so do nanomaterials, many nanoscale measurements, and devices of the future. We discuss the important roles that these contacts can play in preserving key transport and other properties. Initial nanoscale connections and measurements guide the path to future opportunities and challenges ahead. Band alignment and minimally disruptive connections are both targets and can be characterized in both experiment and theory. Chiral assemblies can control the spin properties and thus transport at interfaces. I discuss our initial forays into these areas in a number of materials systems.

Wednesday August 18 2021, 9:40 AM – 10:05 AM (PST), Thursday August 19 2021, 1:40 PM – 2:05 PM (KST)

Distinguished Lecture Series for Young Scientists (Online), Sungkyunkwan University (SKKU), Seoul, South Korea

Atomically Precise Chemical, Physical, Electronic, and Spin Contacts

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Wednesday August 18 2021, 8:10 AM – 8:50 AM (PST)

AAAFM-UCLA 2021, UCLA, Los Angeles, CA, 18-20 August 2021.

Atomically Precise Chemical, Physical, Electronic, and Spin Contacts

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Two seemingly conflicting trends in nanoscience and nanotechnology are our increasing ability to reach the limits of atomically precise structures and our growing understanding of the importance of heterogeneity in the structure and function of molecules and nanoscale assemblies. By having developed the “eyes” to see, to record spectra, and to measure function at the nanoscale, we have been able to fabricate structures with precision as well as to understand the important and intrinsic heterogeneity of function found in these assemblies. The physical, electronic, mechanical, and chemical connections that materials make to one another and to the outside world are critical and are intertwined in terms of their function. Just as the properties and applications of conventional semiconductor devices depend on these contacts, so do nanomaterials, many nanoscale measurements, and devices of the future. We discuss the important roles that these contacts can play in preserving key transport and other properties. Initial nanoscale connections and measurements guide the path to future opportunities and challenges ahead. Band alignment and minimally disruptive connections are both targets and can be characterized in both experiment and theory [1,2]. Chiral assemblies can control the spin properties and thus transport at interfaces [3,4]. I discuss our initial forays into these areas in a number of materials systems.

30 July 2021, 9:00 AM – 9:50 AM (EDT)

The 21st IEEE International Conference on Nanotechnology (IEEE Nano 2021), Montreal, Canada, 28-30 July 2021.

Atomically Precise Chemical, Physical, Electronic, and Spin Contacts and Interfaces

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We are increasing ability to reach the limits of atomically precise structures. By having developed the “eyes” to see, to record spectra, and to measure function at the nanoscale, we have been able to fabricate structures with precision. The physical, electronic, mechanical, and chemical connections that materials make to one another and to the outside world are critical. Just as the properties and applications of conventional semiconductor devices depend on these contacts, so do nanomaterials, many nanoscale measurements, and devices of the future. We discuss the important roles that these contacts can play in preserving key transport and other properties. Initial nanoscale connections and measurements guide the path to future opportunities and challenges ahead. Band alignment and minimally disruptive connections are both targets and can be characterized in both experiment and theory. Chiral assemblies can control the spin properties and thus transport at interfaces. I discuss our initial forays into these areas in a number of materials systems.

26 July 2021, 10:10 AM – 10:50 AM (UTC+8)

AIE20 International Conference, Guangzhou, China, 24-27 July 2021

Nanotechnology Approaches to Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Saturday May 22 2021, 10 AM– 11 AM (Beijing)

SmartMat, Beijing, China. Broadcast Available.

Nanotechnology Approaches to Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Biology functions at the nanoscale. Thus, there are special opportunities not only to make biological measurements using nanotechnology, but also to interact directly in order to influence biological outcomes. Nanoscience and nanotechnology developed from chemistry, physics, biology, engineering, medicine, toxicology, and a host of other fields. Along the way, we taught each other our problems, challenges, and approaches. The interdisciplinary communication skills that were developed and are now part of our training remain unique to the field. As a result, nanoscience contributes to a wide range of other fields, such as neuroscience and the microbiome.

Friday May 21 2021, 9 AM – 10 AM (PST)

Micron TLP Tech Talk Forum, Micron Technology

Atomically Precise Chemical, Physical, Electronic, and Spin Contacts and Interfaces

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Two seemingly conflicting trends in nanoscience and nanotechnology are our increasing ability to reach the limits of atomically precise structures and our growing understanding of the importance of heterogeneity in the structure and function of molecules and nanoscale assemblies. By having developed the “eyes” to see, to record spectra, and to measure function at the nanoscale, we have been able to fabricate structures with precision as well as to understand the important and intrinsic heterogeneity of function found in these assemblies. The physical, electronic, mechanical, and chemical connections that materials make to one another and to the outside world are critical. Just as the properties and applications of conventional semiconductor devices depend on these contacts, so do nanomaterials, many nanoscale measurements, and devices of the future. We discuss the important roles that these contacts can play in preserving key transport and other properties. Initial nanoscale connections and measurements guide the path to future opportunities and challenges ahead. Band alignment and minimally disruptive connections are both targets and can be characterized in both experiment and theory. Chiral assemblies can control the spin properties and thus transport at interfaces. I discuss our initial forays into these areas in a number of materials systems.

Tuesday May 11 2021, 5 AM – 7 AM (PST)

ASGCT 24th Annual Meeting, American Society of Gene & Cell Therapy, 11-14 May 2021.

Poster Presentation: Slippery Liquid-Infused Porous Surfaces (SLIPS) for Cell Deformation Enabling Intracellular Cargo Delivery

Isaura Frost, Department of Bioengineering and Medical Scientist Training Program at David Geffen School of Medicine, UCLA, Los Angeles, CA 90095

Intracellular delivery technologies that are scalable, cost-effective, and efficient are required to process large populations of cells more effectively into gene and cellular therapy products for patient care. Existing microfluidic approaches that leverage cellular membrane deformation to render cells transiently porous as cells pass through narrow microchannels require specialized equipment and are often hindered by issues with clogging that leads to device failure within minutes. We are developing and testing a rapid deformation technique that consists of passing cells through the pores of slippery liquid-infused porous surface (SLIPS)-modified polyethylene terephthalate (PET) cell culture inserts by application of negative pressure. Delivery of green fluorescent protein (GFP) expression plasmids is demonstrated in Jurkat cells with transfection efficiencies of up to 40% and >80% viability. Fluorescently labeled dextran delivery is demonstrated in both immortalized and primary cell types. These bioinspired omniphobic coatings reduce biofouling and circumvent issues that have precluded existing technologies to enable rapid and sustainable transport of biomolecular payloads to target cell populations. Importantly, these devices can be scaled to process millions of cells in a short time while maintaining costs to a minimum (<$10 per experiment). These good manufacturing practice (GMP)-compatible, table-top approaches do not require specialized equipment, viral vectors, or reagents, offering a versatile and straightforward solution for manufacturing future stem cell-based gene and cellular therapies.”

Monday 26 April 2021

9:30 – 10:15 AM (Beijing Time), Sunday 25 April 2021, 6:30 – 7:15 PM (PST), IEEE NEMS 2021, Xiamen, China, 25-29 April 2021.

Atomically Precise Chemical, Physical, Electronic, and Spin Contacts

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

The physical, electronic, mechanical, and chemical connections that materials make to one another and to the outside world are critical and are intertwined in terms of their function. Just as the properties and applications of conventional semiconductor devices depend on these contacts, so do nanomaterials, many nanoscale measurements, and devices of the future. We discuss the important roles that these contacts can play in preserving key transport and other properties.

Initial nanoscale connections and measurements guide the path to future opportunities and challenges ahead. Band alignment and minimally disruptive connections are both targets and can be characterized in both experiment and theory. Chiral assemblies can control the spin properties and thus transport at interfaces. I discuss our initial forays into these areas in a number of materials systems.

Thursday 11 March 2021, 7:30 AM (PST)

World Nano Congress on Advanced Science and Technology (WNCST-2021), Tamil Nadu, India, 8-12 March 2021.

Atomically Precise Chemical, Physical, Electronic, and Spin Contacts

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Two seemingly conflicting trends in nanoscience and nanotechnology are our increasing ability to reach the limits of atomically precise structures and our growing understanding of the importance of heterogeneity in the structure and function of molecules and nanoscale assemblies. By having developed the “eyes” to see, to record spectra, and to measure function at the nanoscale, we have been able to fabricate structures with precision as well as to understand the important and intrinsic heterogeneity of function found in these assemblies. The physical, electronic, mechanical, and chemical connections that materials make to one another and to the outside world are critical and are intertwined in terms of their function. Just as the properties and applications of conventional semiconductor devices depend on these contacts, so do nanomaterials, many nanoscale measurements, and devices of the future. We discuss the important roles that these contacts can play in preserving key transport and other properties. Initial nanoscale connections and measurements guide the path to future opportunities and challenges ahead. Band alignment and minimally disruptive connections are both targets and can be characterized in both experiment and theory. Chiral assemblies can control the spin properties and thus transport at interfaces. I discuss our initial forays into these areas in a number of materials systems.

Sunday 28 February 2021, 10:30 AM – 11 AM (IST)

National Science Day Celebration, Department of Chemistry, Uka Tarsadia University, Bardoli, India.

Adventures in Nanoscience and Nanotechnology

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Wednesday 24 February 2021, 9:45 – 10:30 AM (SAST)

Middle East and North Africa (MENA) International Conference on Biosensors 2021, 24-25 February 2021.

Nanoscience & Nanotechnology Approaches to Biosensing

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Friday 15 January 2021, 4:00 – 4:45 PM (PST)

Academicians Forum on Interdisciplinary Biology and Inaugural Ceremony of Exploration, Kaifeng, China (Zoom), 15-16 January 2021.

Nanotechnology Approaches to Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Biology functions at the nanoscale. Thus, there are special opportunities not only to make biological measurements using nanotechnology, but also to interact directly in order to influence biological outcomes. Nanoscience and nanotechnology developed from chemistry, physics, biology, engineering, medicine, toxicology, and a host of other fields. Along the way, we taught each other our problems, challenges, and approaches. The interdisciplinary communication skills that were developed and are now part of our training remain unique to the field. As a result, nanoscience contributes to a wide range of other fields, such as neuroscience and the microbiome.

Wednesday 13 January 2021, 8:05 – 10:05 AM (PST)

Virtual National Nanotechnology Initiative (NNI) Strategic Planning Stakeholder Workshop, 11-13 January 2021.

Measuring Impact

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Sunday 13 December 2020, 5:30 – 5:50 AM (PST)

The Israel Vacuum Society

Atomically Precise Chemical, Physical, Electronic, and Spin Contacts

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Two seemingly conflicting trends in nanoscience and nanotechnology are our increasing ability to reach the limits of atomically precise structures and our growing understanding of the importance of heterogeneity in the structure and function of molecules and nanoscale assemblies. By having developed the “eyes” to see, to record spectra, and to measure function at the nanoscale, we have been able to fabricate structures with precision as well as to understand the important and intrinsic heterogeneity of function found in these assemblies. The physical, electronic, mechanical, and chemical connections that materials make to one another and to the outside world are critical. Just as the properties and applications of conventional semiconductor devices depend on these contacts, so do nanomaterials, many nanoscale measurements, and devices of the future. We discuss the important roles that these contacts can play in preserving key transport and other properties. Initial nanoscale connections and measurements guide the path to future opportunities and challenges ahead. Band alignment and minimally disruptive connections are both targets and can be characterized in both experiment and theory. Chiral assemblies can control the spin properties and thus transport at interfaces. I discuss our initial forays into these areas in a number of materials systems.

Thursday 10 December 2020, 7 – 9 AM (PST)

Nano Letters Nanoscience Global Lecture Series

Atomically Precise Chemical, Physical, Electronic, and Spin Contacts

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Two seemingly conflicting trends in nanoscience and nanotechnology are our increasing ability to reach the limits of atomically precise structures and our growing understanding of the importance of heterogeneity in the structure and function of molecules and nanoscale assemblies. By having developed the “eyes” to see, to record spectra, and to measure function at the nanoscale, we have been able to fabricate structures with precision as well as to understand the important and intrinsic heterogeneity of function found in these assemblies. The physical, electronic, mechanical, and chemical connections that materials make to one another and to the outside world are critical. Just as the properties and applications of conventional semiconductor devices depend on these contacts, so do nanomaterials, many nanoscale measurements, and devices of the future. We discuss the important roles that these contacts can play in preserving key transport and other properties. Initial nanoscale connections and measurements guide the path to future opportunities and challenges ahead. Band alignment and minimally disruptive connections are both targets and can be characterized in both experiment and theory. Chiral assemblies can control the spin properties and thus transport at interfaces. I discuss our initial forays into these areas in a number of materials systems.

Wednesday 21 October 2020, 9:10 PM PST

KSBB Fall Meeting and International Symposium, Suwon Convention Center, South Korea

Nanotechnology Approaches to Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Biology functions at the nanoscale. Thus, there are special opportunities not only to make biological measurements using nanotechnology, but also to interact directly in order to influence biological outcomes. Nanoscience and nanotechnology developed from chemistry, physics, biology, engineering, medicine, toxicology, and a host of other fields. Along the way, we taught each other our problems, challenges, and approaches. The interdisciplinary communication skills that were developed and are now part of our training remain unique to the field. As a result, nanoscience contributes to a wide range of other fields, such as neuroscience and the microbiome.

Tuesday 20 October 2020, 10 AM (Bejing), Monday 19 October, 7 PM PST

SmartMat Lecture, Tianjin University, Tianjin, China

Chemical, Physical, and Electronic Nanoscale Contacts and Interfaces

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

NanoScientific Symposium for a Changing World (NSCW), 14-15 October 2020.

Nanotechnology Approaches to Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Biology functions at the nanoscale. Thus, there are special opportunities not only to make biological measurements using nanotechnology, but also to interact directly in order to influence biological outcomes. Nanoscience and nanotechnology developed from chemistry, physics, biology, engineering, medicine, toxicology, and a host of other fields. Along the way, we taught each other our problems, challenges, and approaches. The interdisciplinary communication skills that were developed and are now part of our training remain unique to the field. As a result, nanoscience contributes to a wide range of other fields, such as neuroscience and the microbiome.

https://www.youtube.com/embed/Vfwpzyev3tU

Thursday 15 October 2020

PhD Student Exit Seminar, Young Hall 2033, UCLA, Los Angeles, California

Implantable and Wearable Bioelectronics: Eavesdropping on Chemical Signaling

Chuanzhen Zhao, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

Biomarkers from the human body can provide dynamic and powerful insight a broad spectrum of health conditions. Monitoring biomarkers in bodily fluids will improve and advance prediction, screening, diagnosis, and treatment of disease. At present, however, the ability to study and to track the everchanging mixtures of chemicals inside and on the human body is limited. For example, chemical communication between neurons plays central roles in information processing in the brain, yet technologies for neurochemical recordings are limited. For the past five years, I have focused on developing transformative biosensors towards in vivo neurotransmitter monitoring to advance our understanding of brain activity.

To achieve this goal, we developed ultrathin (~3-nm) In₂O₃ field-effect transistor (FET) biosensors, where DNA sequences (aptamers) covalently functionalized to the device surfaces enable specific, high-sensitivity molecular recognition. A high-throughput, wafer-scale, and low-cost nanolithographic approach (chemical lift-off lithography) was developed and applied for the fabrication of nanoscale FETs, which are the functional core of these sensors. Building on the capabilities of these aptamer-FET biosensors, we developed multiplexed sensors that simultaneously target several important biomarkers, including dopamine, serotonin, glucose, phenylalanine, and cortisol.

We have designed and fabricated implantable neurochemical probes and wearable bioelectronics using micro-electro-mechanical-system technologies. We performed ex vivo and in vivo experiments with implanted neural probes to monitor neurotransmitters, e.g., serotonin, in living, conscious animals. The technologies we are developing will advance our understanding of healthy brain function in relation to complex behavior, as well as corresponding dysfunction in psychiatric and neurodegenerative disorders.

Monday 14 September 2020, 6:00 PM (PST), Webinar

Nanyang Technological University, Singapore.

Adding the Chemical Dimension to Lithography at All Scales: Enabling Cellular Therapies & Other Adventures in Biology and Medicine

By controlling the exposed chemical functionality of materials from the submolecular through the centimeter scale, we have enabled new capabilities in biology, medicine, and other areas. I will discuss current and upcoming advances and will pose the challenges that lie ahead in creating, developing, and applying new tools using this capability. These advances include using biomolecular recognition in sensor arrays to probe dynamic chemistry in the brain and microbiome systems. In other areas, we introduce biomolecular payloads into cells for gene editing at high throughput for off-the-shelf solutions targeting hemoglobinopathies, immune diseases, and cancers. We circumvent the need for viral transfection and electroporation, both of which have significant disadvantages in safety, throughput, cell viability, and cost. Mechanical deformation can make cell membranes transiently porous and enable gene-editing payloads to enter cells. These methods use specific chemical functionalization and control of surface contact and adhesion in microfluidic channels.

Tuesday 15 September 2020, 12:00 PM – 1:00 PM (EDT)

University of Toronto, Institute of Biomaterials and Biomedical Engineering, Toronto, ON, Canada.

Adding the Chemical Dimension to Lithography at All Scales: Enabling Cellular Therapies & Other Adventures in Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Wednesday 23 September 2020, 10:30 AM – 11:15 AM (Korea Time)

1st KAIST Emerging Materials e-Symposium, South Korea, 21 – 25 September 2020

Nanotechnology Approaches to Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Biology functions at the nanoscale. Thus, there are special opportunities not only to make biological measurements using nanotechnology, but also to interact directly in order to influence biological outcomes. Nanoscience and nanotechnology developed from chemistry, physics, biology, engineering, medicine, toxicology, and a host of other fields. Along the way, we taught each other our problems, challenges, and approaches. The interdisciplinary communication skills that were developed and are now part of our training remain unique to the field. As a result, nanoscience contributes to a wide range of other fields, such as neuroscience and the microbiome.

Thursday 25 September 2020, 9:15 AM

NanoFlorida 2020, Online Seminar, Miami, Florida

Nanotechnology Approaches to Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Thursday 30 July 2020, 11:15 AM – 11:45 AM (PST)

International Society of RNA Nanotechnology and Nanomedicine (ISRNN) Webinar Series, Ohio State University
Columbus, Ohio, 29-30 July 2020.

Nanotechnology Approaches to Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Biology functions at the nanoscale. Thus, there are special opportunities not only to make biological measurements using nanotechnology, but also to interact directly in order to influence biological outcomes. Nanoscience and nanotechnology developed from chemistry, physics, biology, engineering, medicine, toxicology, and a host of other fields. Along the way, we taught each other our problems, challenges, and approaches. The interdisciplinary communication skills that were developed and are now part of our training remain unique to the field. As a result, nanoscience contributes to a wide range of other fields, such as neuroscience and the microbiome.

Thursday 9 July 2020, 11 AM – 12 PM

Speaker Series at Illumina, Online Seminar, San Diego, California.

Nanotechnology Approaches to Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Biology functions at the nanoscale. Thus, there are special opportunities not only to make biological measurements using nanotechnology, but also to interact directly in order to influence biological outcomes. Nanoscience and nanotechnology developed from chemistry, physics, biology, engineering, medicine, toxicology, and a host of other fields. Along the way, we taught each other our problems, challenges, and approaches. The interdisciplinary communication skills that were developed and are now part of our training remain unique to the field. As a result, nanoscience contributes to a wide range of other fields, such as neuroscience and the microbiome.

Tuesday 16 June 2020, 8 AM

ICN2 Seminar, Online Seminar, Barcelona, Spain.

Nanotechnology Approaches to Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Biology functions at the nanoscale. Thus, there are special opportunities not only to make biological measurements using nanotechnology, but also to interact directly in order to influence biological outcomes. Nanoscience and nanotechnology developed from chemistry, physics, biology, engineering, medicine, toxicology, and a host of other fields. Along the way, we taught each other our problems, challenges, and approaches. The interdisciplinary communication skills that were developed and are now part of our training remain unique to the field. As a result, nanoscience contributes to a wide range of other fields, such as neuroscience and the microbiome.

Thursday 4 June 2020, 12 PM

PhD Student Exit Seminar, UCLA Department of Chemistry & Biochemistry, Los Angeles, California

Lipid and Acoustic Strategies for Chemical Patterning and Gene Delivery

Jason N Belling, Department of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

Supported lipid membranes are versatile biomimetic coatings for thechemical functionalization of inorganic surfaces. Developing simple andeffective fabrication strategies to form supported lipid membranes withmicropatterned geometries is a long-standing challenge. We demonstrate how thecombination of chemical lift-off lithography (CLL) and easily prepared lipidbicelle nanostructures can yield micropatterned, supported lipid membranes ongold surfaces with high pattern resolution, conformal character, andbiofunctionality. We further showed that bicelles can be used as a passivationstrategy to reduce fouling in microfluidics designed for intracellulardelivery. Of note, constricted microfluidic geometries that deform cells to afraction of their diameter have emerged as a promising technology thatfacilitates high-performance gene editing. Unfortunately, these technologiesare inherently limited by device lifetime due to the accumulation of cellulardebris and eventual clogging. As these microfluidic technologies transitionfrom conceptual prototypes to functional tools, there is a need to developnext-generation platforms with high-throughput and long lifespan. Towards thisgoal, we report the design and application of lipid-coated microfluidic and acoustofluidicplatforms that are able to deliver plasmid rapidly and safely to model andhuman primary cell types. Our lipid-coated microfluidic system demonstrated adramatic reduction in fouling, with blocking efficiency towards nonspecificprotein adsorption and cell adhesion as compared to bare polydimethylsiloxaneand glass microfluidic devices. We explored the application of our lipid layerby coating constricted microfluidic channels designed for the intracellulardelivery of biomolecular cargo. We observed significant reductions in theaccumulation of cell debris and delivery of large dextran molecules and plasmidwhile retaining high viability. In parallel, we developed an acoustofluidicmethod to deliver plasmids to immortalized and primary human cell types, basedon the permeabilization of cell membranes with acoustic waves and shearingagainst the walls of glass microcapillaries. This acoustofluidic-mediatedapproach achieves fast and efficient intracellular delivery of an enhancedgreen fluorescent protein–expressing plasmid to cells at a scalable throughputof 200,000 cells/min in a single channel. Analyses of intracellular deliveryand nuclear membrane rupture revealed mechanisms underlying acoustofluidicdelivery and successful gene expression. Collectively, our studies show that thesetechnologies are promising platforms for gene delivery and useful tools forinvestigating membrane repair.

Thursday 28 May 2020

PhD Student Exit Seminar, UCLA Department of Chemistry & Biochemistry, Los Angeles, California

Nanoscale Vibrational Spectroscopy of Gold-Cyanide Self-Assemblies: From Monolayers to Crystallites

Kristopher Barr, Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA 90095

My thesis work focuses on the integration of scanning tunneling microscopy with infrared spectroscopy, to provide unprecedented Ångstrom-scale resolution in surface imaging with spatially correlated chemical specificity. Scanning probe techniques generally lack chemical information. Inspired by recent advances coupling optical spectroscopies with scanning probe microscopies, I have developed a nanoscale infrared spectroscopic method applying scanning tunneling microscope probe tips as nanoantennas to obtain multiplexed molecular vibrational signals utilizing a Fourier transform interferometer at room temperature and ambient pressure. The sensitivity of the tunneling junction and nanoscale probe area enables the measurement of vibrational spectra orders of magnitude below the diffraction limit. I substantiated the effectiveness of this instrument by designing an air- and temperature-stable model system characterized by infrared absorption that couples to the electronic states of the gold substrate. Specifically, aurous cyanide (AuCN) self-assembled monolayers satisfy these requirements with the added benefit that its IR absorption lies outside of the carbon dioxide and water windows, thereby maintaining a high signal-to-noise ratio for these experiments. These atomically pristine hexagonal close-packed AuCN monolayers exhibit a strong absorption at 2140 cm⁻¹. Upon thermal annealing, the surface rearranges into a ribbon structure with a blue-shifted absorption to 2230 cm⁻¹. The unique vibrational contrast in AuCN monolayers resulting from thermally induced structural changes serves as an ideal model system for the new infrared scanning tunneling microscope (IR-STM). Upon prolonged vapor deposition, the self-assembled cyanide monolayers reconfigure into large-scale AuCN crystals, giving two distinct morphologies and significantly different vibrational modes, compared to the AuCN monolayer structures. Once again, temperature can tune gold-cyanide orientation and long-range ordering. This work provides new insights for controlled surface-mediated crystal growth in AuCN systems. Ultimately, combining with the chemical information gained from the developed IR-STM, surface-mediated growth will enable new methodologies for fabricating next-generation nanoscale semiconductors. Nanoscale semiconductors based on AuCN that are similar to nanoribbon structures have been demonstrated to be useful for nanoelectronics as well as in catalytic applications.

Thursday 28 May 2020, 10:00 – 11:00 PM

Uka Tarsadia Frontiers in Chemistry Conference, India, May 29 – May 30, 2020

Nanotechnology Approaches to Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Biology functions at the nanoscale. Thus, there are special opportunities not only to make biological measurements using nanotechnology, but also to interact directly in order to influence biological outcomes. Nanoscience and nanotechnology developed from chemistry, physics, biology, engineering, medicine, toxicology, and a host of other fields. Along the way, we taught each other our problems, challenges, and approaches. The interdisciplinary communication skills that were developed and are now part of our training remain unique to the field. As a result, nanoscience contributes to a wide range of other fields, such as neuroscience and the microbiome.

Tuesday 12 May 2020, 5:30 – 6:30 PM

Poster Presentation at the ASGCT 23rd Annual Meeting, May 12 – May 15, 2020

Poster (Online Presentation): Acoustofluidic Sonoporation Gene Delivery for Cancer Immunotherapy

Yao Gong, California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA, United States.

T-cell-based immunotherapies that leverage the collection and genetic modification of patients’ T-cells to express chimeric antigen receptors (CAR) specific for tumor antigens represent a significant advance in the treatment of relapsed and refractory leukemia and B-cell lymphomas. The effective manufacturing of CAR-T cell products for patient care requires target cell populations to be engineered rapidly, efficiently, safely, and cost effectively. Toward this goal, we report an acoustofluidic strategy to deliver a CD19-specific CAR transgene to T-cells in vitro by shearing cells against a glass microcapillary wall. Mechanistic investigations of cell membrane permeability post-acoustofluidic treatment reveal that the cell and nuclear membranes are disrupted in model cell types, promoting the entry of DNA and other biomolecular cargoes for gene-editing into cells. To further enhance the performance of engineered T-cells and achieve uniform CAR expression, we have configured our platform to deliver CRISPR/Cas9-based cargoes that direct the CAR to the T-cell receptor α constant (TRAC) locus. Overall, this acoustic-based transfection strategy represents a versatile platform technology that potentially enables a wide range of therapeutic payloads to be delivered to target cells for applications spanning both the cancer immunotherapy and stem cell-based gene therapy spaces.

Thursday 30 April 2020

ACS Spring 2020

Surface-Mediated Crystal Growth Of Aurous Cyanide From Molecular Self-Assembled Monolayers

Kristopher Barr, Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA 90095

Tuesday 3 March 2020, 5:30 – 7:30 PM

APS March Meeting 2020, Room 108, Colorado Convention Center, Colorado, March 2-6, 2020

Fourier transform infrared scanning tunneling microscopy: Measuring vibrational modes at the nanoscale

Kristopher Barr, Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA 90095

Scanning probe microscopy has enabled unprecedented surface imaging with better than atomic resolution. Recent advances have led to successful integration of optical spectroscopies with various scanning probe microscopies. In this work, we use the scanning tunneling microscope tip as a nano antenna and a multiplexed signal from a bench-top Fourier-transform interferometer to discover vibrational modes at the nanoscale. By back illuminating our gold on sapphire samples, we are able to excite molecular adsorbates into vibrationally excited states evanescently, thus creating perturbing the conductance of the STM junction. We use cyanide on gold as a proof-of-concept system because of its distinct vibrational spectra, its stability under ambient conditions, and our ability to control the molecular interactions. In previous work, we have demonstrated direct control of the gold cyanide molecular packing structures – cubic or hexagonal close packed – and can attribute a vibrational mode from Raman and infrared spectroscopy to each phase. This custom-built instrument operates under ambient conditions, enabling us to image chemical structure with single-molecule resolution on a variety of systems.

Monday 2 March 2020

Pittcon, McCormick Place, Chicago, Illinois, 1-5 March 2020

Adding the Chemical Dimension to Lithography: Enabling Capture and Sensing of Signaling Molecules, Exosomes, and Cells

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Monday, 17 February 2020, Nano Revolution: Taking Health and Medicine to the Next Level, Charles Perkins Centre Auditorium, The University of Sydney, Sydney, Australia.

Nanotechnology Approaches to Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Biology functions at the nanoscale. Thus, there are special opportunities not only to make biological measurements using nanotechnology, but also to interact directly in order to influence biological outcomes. Nanoscience and nanotechnology developed from chemistry, physics, biology, engineering, medicine, toxicology, and a host of other fields. Along the way, we taught each other our problems, challenges, and approaches. The interdisciplinary communication skills that were developed and are now part of our training remain unique to the field. As a result, nanoscience contributes to a wide range of other fields, such as neuroscience and the microbiome.

Friday, 14 February 2020, 12 – 1 PM, University of New South Wales, Sydney, Australia.

Adding the Chemical Dimension to Lithography at All Scales: Enabling Cellular Therapies & Other Adventures in Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Tuesday 11 February 2020, 9:15 to 10 AM

International Conference on Nanoscience and Nanotechnology (ICONN), Brisbane Convention & Exhibition Center, Great Hall 1 & 2, Brisbane, Australia, 9-13 February 2020

Adding the Chemical Dimension to Lithography at All Scales: Enabling Cellular Therapies & Other Adventures in Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095Paragraph

Saturday 8 February 2020, 1:20 – 1:40 PM

Energy and Environmental Materials 2020 (EEM 2020), Surfers Paradise, Australia, 6-8 February 2020

Precise Chemical, Physical, and Electronic Nanoscale Contacts

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Saturday 1 February 2020

Mindshare LA: It Came from Nano Space, Cross Campus, 800 Wilshire Blvd 2nd Floor, Los Angeles, CA 90017

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Thursday 23 January 2020, 4 PM

Furman University, Plyler 231, Greenville, South Carolina

Advances in Surface Science and Next-Generation Electronic Biosensors
Kevin M. Cheung, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

Chemical lift-off lithography (CLL) is a subtractive soft-lithographic technique used to pattern self-assembled monolayers (SAMs) containing functional alkanethiolates on Au surfaces. Alkanthiolate molecules, along with a single monolayer of Au, are removed in this process by oxygen-plasma activated polydimethysiloxane (PDMS) stamps. Monolayers patterned via CLL are robust, in contrast to conventional soft-lithography, enabling high-fidelity patterning over a dynamic range of feature sizes (millimeter to nanometer). Recently, we have advanced CLL to pattern additional surfaces, including other coinage metals (e.g., Pt, Pd, Ag, Cu), reactive and transition metals (e.g., Ni, Ti, Al), and semiconductors (e.g., Ge). This process has a wide range of applications, including patterning of supported metal monolayers, as well as the simple, convenient fabrication of field-effect transistors (FETs). We have designed and developed FET biosensors coupled to rationally designed and chemically synthesized oligonucleotide sequences with molecular recognition capabilities, termed aptamers, for the detection of a diverse range of biologically important small-molecule targets (e.g.,neurotransmitters, amino acids, sugars, lipids). Upon target capture, aptamers undergo conformational changes that redistribute charge densities on FET surfaces resulting in measurable changes in conductance. We demonstrate the detection of targets in full ionic strength biological fluids, with high specificity and selectivity, over large concentration ranges with low detection limits. Using this platform, we are developing sensors for the direct detection of the amino acid phenylalanine for potential point-of-care use for patients with phenylketonuria (PKU), a common genetic disorder that results in elevated and potentially harmful levels of phenylalanine in the blood and brain. Phenylalanine aptamer-FETs showed high sensitivity and selectivity towards phenylalanine versus similarly structured molecules, and were able to differentiate physiological phenylalanine concentrations in serum from mice treated with a phenylalanine hydroxylase inhibitor (i.e., a PKU mouse model). Performing FET measurements under physiologically relevant conditions and elucidating sensing mechanisms is necessary for ultimate use in disease diagnostics and clinical point-of-care applications.

Wednesday 11 December 2019, 9:15 – 10 AM

10^th International Conference of the African Materials Research Society (AMRS2019), Tanzania, December 10-13 2019

Global Opportunities in Nanotechnology

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

By controlling the exposed chemical functionality of materials from the submolecular through the centimeter scale, we have enabled new capabilities in biology, medicine, and other areas. I will discuss current and upcoming advances and will pose the challenges that lie ahead in creating, developing, and applying new tools using this capability. These advances include introducing biomolecular payloads into cells for gene editing at high throughput for off-the-shelf solutions targeting hemoglobinopathies, immune diseases, and cancers. We circumvent the need for viral transfection and electroporation, both of which have significant disadvantages in safety, throughput, cell viability, and cost. Mechanical deformation can make cell membranes transiently porous and enable gene-editing payloads to enter cells. These methods use specific chemical functionalization and control of surface contact and adhesion in microfluidic channels.

Wednesday 20 November 2019, 11 AM – 12 PM

National University of Singapore, Singapore

Precise Chemical, Physical, and Electronic Nanoscale Contacts
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

The physical, electronic, mechanical, and chemical connections that materials make to one another and to the outside world are critical. Just as the properties and applications of conventional semiconductor devices depend on these contacts, so do nanomaterials, many nanoscale measurements, and devices of the future. We discuss the important roles that these contacts can play in preserving key transport and other properties. Initial nanoscale connections and measurements guide the path to future opportunities and challenges ahead. Band alignment and minimally disruptive connections are both targets and can be characterized in both experiment and theory. I discuss our initial forays into this area in a number of materials systems.

Tuesday 19 November 19 2019, 6:30 PM

Australian High Commission and Wildfire Media, Switzer, Singapore

The Impact of STEM on Business and Society

Mario Herrero, Chief Research Scientist of CSIRO Agriculture and Food

Adam Switzer, Associate Chair (academic) at the Asian School of the Environment

Jane Lim, Assistant CEO of the Infocomm Media Development Authority

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Juliana Chan (Moderator), CEO of Wildtype Media Group, Editor-in-Chief of Asian Scientist Magazine

Sunday 17 November 2019, 2:30 – 3 PM

ACS Innovation in Materials Science & Technology, Nanyang Technological University and National University of Singapore, Singapore, November 17-19 2019

Thursday 14 November 2019

2019 CTOS Annual Meeting, Hilton Tokyo in Tokyo, Japan, November 13 – 16 2019

Nanotechnologies For Capture and Release of Ewing Sarcoma-Derived Circulating Tumor Cells
Steven Jonas, California NanoSystems Institute and Department of Pediatrics, UCLA, Los Angeles, CA 90095

Circulating tumor cells (CTCs) represent an ideal “liquid biopsy” source for well-preserved messenger RNA (mRNA) that can be used for molecular profiling of solid tumors. Existing CTC analysis platforms have been difficult to apply to sarcomas, in part, due to technical challenges in how to best target malignant cells for selective capture. Here, we describe initial tests and demonstrations of a system for CTC capture that leverages advances in nanomaterials and microfluidics to enable enumeration of CTCs derived from Ewing Sarcoma (EWS). We utilize CTC counts and copy numbers of EWSR1 gene rearrangements as metrics for device performance, which pave the way for translation of these nanotechnologies as non-invasive diagnostic solutions for guiding treatment intervention and monitoring disease progression in EWS patients.

Thursday 31 October 2019, 12 – 1 PM

PhD Student Exit Seminar, 2033 Young Hall, UCLA Department of Chemistry & Biochemistry, Los Angeles, California

Advances in Surface Patterning and Next-Generation Electronic Biosensors
Kevin M. Cheung, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

Chemical lift-off lithography (CLL) is a subtractive soft-lithographic technique used to pattern self-assembled monolayers (SAMs) containing functional alkanethiolates on gold surfaces. Alkanthiolate molecules, along with a single monolayer of gold, are removed in this process by oxygen-plasma activated polydimethysiloxane (PDMS) stamps. Monolayers patterned via CLL are robust, in contrast to conventional soft-lithography, enabling high-fidelity patterning over a dynamic range of feature sizes (millimeter to nanometer). Recently, we have advanced CLL to pattern additional surfaces, including other coinage metals (e.g., Pt, Pd, Ag, Cu), reactive transition metals (e.g., Ni, Ti, Al), and semiconductors (e.g., Ge). This process has a wide range of applications, including patterning of supported metal monolayers, as well as the simple, convenient fabrication of field-effect transistors (FETs). We have designed and developed FET biosensors coupled to rationally designed and chemically synthesized oligonucleotide sequences with molecular recognition capabilities, termed aptamers, for the detection of a diverse range of biologically important small-molecule targets (e.g., neurotransmitters, amino acids, sugars, lipids). Upon target capture, aptamers undergo conformational changes that redistribute charge densities on FET surfaces resulting in measurable changes in conductance. We demonstrate the detection of targets in full ionic strength biological fluids, with high specificity and selectivity, over large concentration ranges with low detection limits. Using this platform, we are developing sensors for the direct detection of the amino acid phenylalanine for potential point-of-care use for patients with phenylketonuria (PKU), a common genetic disorder that results in elevated and potentially harmful levels of phenylalanine in the blood and brain. Phenylalanine aptamer-FETs showed high sensitivity and selectivity towards phenylalanine versus similarly structured molecules, and were able to differentiate physiological phenylalanine concentrations in serum from mice treated with a phenylalanine hydroxylase inhibitor (i.e., a PKU mouse model). Performing FET measurements under physiologically relevant conditions and elucidating sensing mechanisms is necessary for ultimate use in disease diagnostics and clinical point-of-care applications.

Wednesday 23 October 2019, 3 – 3:40 PM

AVS 66th International Symposium & Exhibition, Columbus, Ohio, October 20-25 2019

Adding the Chemical Dimension to Lithography at All Scales: Enabling Cellular Therapies & Other Adventures in Biology and Medicine
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Thursday, 17 October 2019 from 12:00 PM – 1:00 PM, Young Hall 2033, University of California, Los Angeles, Los Angeles, California.

Interfacing Bacteria with Inorganic Material: Adhesion and Electron Transport

Thomas D. Young, Department of Chemistry & Biochemistry and California NanoSystems, UCLA, Los Angeles, CA 90095

Harnessing the usefulness of micro-organisms necessitates an interface between cells and abiotic surfaces such as electrodes. In this talk, I will describe how our group influenced surface colonization of the bacteria Shewanella oneidensis to facilitate our study of electrical conductivity of the model organisms S. oneidensis and Geobacter sulfurreducens utilizing atomic force microscopy.

To promote attachment of the desired bacteria, we synthesized and assembled glycopolymers onto gold surfaces. Each monomer incorporated into the polymer presents a mannose unit, which binds specifically to proteins on the species of interest. The multivalency of the glycopolymers enhanced the persistence of attached cells on the surface. When rinsed with a competitive inhibitor, the glycopolymer-functionalized surfaces retained more cells than self-assembled monolayers terminated by a single mannose unit. When the competitor was co-deposited with the cell culture and provided time to equilibrate, the enhanced adhesiveness of the glycopolymers was removed. This suggests kinetic control over the retention of attached cells and not a thermodynamic result, which has been an interpretation of the cluster glycoside effect. Using these features of the glycopolymer we demonstrated enrichment of the number of wild-type strain of bacteria against a ΔmshA-D knockout strain and induced where the bacteria attach on a molecular pattern.

Thursday, September 26 2019 from 12:00 PM – 1:00 PM, Distinguished Speaker Seminar, KAUST, Saudi Arabia.

Adding the Chemical Dimension to Lithography at All Scales

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Tuesday, September 16 2019 from 2:00 PM – 2:45 PM, 9th International Conference on Nanomaterials: Applications & Properties, Odessa, Ukraine, September 15-20 2019.

Choosing Scientific Problems and the Resulting Papers
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

We will discuss both personal and editorial experiences of what has led to interesting science and to interesting papers. A specific advantage of nanoscience andnanotechnology has been that we have taught each other approaches from different underlying and parent fields, we have shared our scientific problems, and we have collaborated to look at what new approaches are needed. This coordination has led to new opportunities to move into unexplored areas and to address refractory problemsat and beyond the nanoscale.

Tuesday, September 16 2019 from 9:00 AM – 9:45 AM, 9th International Conference on Nanomaterials: Applications & Properties, Odessa, Ukraine, September 15-20 2019.

Thursday, August 29 2019 from 8:00 AM – 8:20 AM, ACS Fall 2019 National Meeting & Exposition, San Diego Ballroom Salon A (ANYL 562) – Marriott Marquis San Diego Marina, San Diego, CA, August 25-29 2019.

Nucleic-acid-functionalized field-effect transistors for biomedical applications

Kevin M. Cheung, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

We have designed and developed ultrathin-film field-effect transistors (FETs) coupled to rationally designed and chemically synthesized oligonucleotide sequences with molecular recognition capabilities, termed aptamers, for the detection of a diverse range of biologically important small-molecule targets (e.g., neurotransmitters, amino acids, sugars, lipids). Upon target capture, aptamers undergo conformational changes that redistribute charge densities on FET surfaces resulting in measurable changes in conductance. We demonstrate the detection of targets in full ionic strength biological fluids, with high specificity and selectivity, over large concentration ranges with low detection limits. Using this platform, we are developing sensors for the direct detection of the amino acid phenylalanine for potential point-of-care use for patients with phenylketonuria (PKU), a common genetic disorder that results in elevated and potentially harmful levels of phenylalanine in the blood and brain. Three phenylalanine-specific DNA sequences were investigated to determine sensor responses contingent on different primary base sequences, secondary structures, and target affinities. Phenylalanine aptamer-FETs showed high sensitivity and selectivity towards phenylalanine versus similarly structured molecules, and were able to differentiate physiological phenylalanine concentrations in serum from mice treated with a phenylalanine hydroxylase inhibitor (i.e., a PKU mouse model). In parallel, we have extended this FET biosensor platform for the detection and discrimination of single-nucleotide polymorphisms. We demonstrate the ability of DNA-functionalized FETs to distinguish hybridization between fully complementary DNA sequences, and analogous sequences with different types and locations of SNPs. Performing FET measurements under physiologically relevant conditions and elucidating sensing mechanisms is necessary for ultimate use in disease diagnostics and clinical point-of-care applications.

Thursday, August 29 2019 from 11:15 AM – 11:35 AM, ACS Fall 2019 National Meeting & Exposition, San Diego Ballroom Salon A (ANYL-571) – Marriott Marquis San Diego Marina, San Diego, CA, August 25-29 2019.

Advantages of gallium indium eutectic contacts for In₂O₃ field-effect transistors

Sara Rahimnejad, Logan Stewart, Chuanzhen Zhao, Anne M. Andrews, Paul S. Weiss

Using eutectic gallium indium (eGaIn), a room-temperature liquid-metal alloy, we fabricated ultrathin In₂O₃ field-effect transistor (FET) devices without the need for electron-beam physical vapor deposition. A drop (~ 10 uL) of eGaIn was placed on the photolithography patterned Si wafer. Eutectic gallium indium was simply then spread onto the surface.The eGaIn coated wafer was briefly immersed in a vertical manner in an ultrasonic bath, of acetone; the removal of the protective coating of photoresist in an ultrasonic bath of acetone leaves behind patterned liquid metal contacts. The low work function of eGaIn reduces the Schottky barrier at the In₂O₃/eGaIn junction relative to In₂O₃ with Au or Ag contacts. The native gallium oxide provides excellent wetting and matches the electronic structure of the functional indium oxide closely. Incorporation of liquid metal contacts into device architectures is a step towards developing soft, flexible, sensors for high-throughput point-of-care screening and diagnosis. By using this liquid metal alloy, we can simplify the fabrication process, significantly reducing device processing time and cost of production for transistor-based devices.

Thursday, August 29 2019 from 3:40 PM – 4:00 PM, ACS Fall 2019 National Meeting & Exposition, Rancho Santa Fe 2 (ANYL-580) – Marriott Marquis San Diego Marina, San Diego, CA, August 25-29 2019.

All-dielectric, mid-infrared metasurfaces for vibrational circular dichroism enhancement

John Abendroth, Materials Science and Engineering, Stanford University, San Jose, California, United States

Nanophotonic approaches using plasmonic and dielectric antennas to enhance both the intensity and chirality of light amplify selectively the rate of absorption of one enantiomer over its mirror image. These strategies have primarily aimed to increase enantioselective absorption by chiral molecules at UV and visible frequencies to achieve greater sensitivity in chiral detection using circular dichroism spectroscopy. Alternatively, chiral-optical enhancement of vibrational excitations using nanophotonic platforms in the mid-infrared has not yet been extensively explored. Vibrational optical activity is a spectroscopic probe of molecular chirality that provides complementary structural information to electronic circular dichroism in the UV regime, and enables unambiguous determination of absolute handedness in combination with density functional theory calculations. To enhance circular dichroism strength for chiral chemical analysis by vibrational spectroscopies, we designed periodic arrays of subwavelength dielectric antennas termed “metasurfaces” capable of producing amplified, circularly polarized electromagnetic near fields upon excitation with linearly polarized light in the mid-infrared region. Thus, metasurfaces would enable the use of spectroscopic methods that are inherently incapable of chiral discrimination for stereochemical analysis of chiral compounds, and to monitor enantiomeric purity in chemical reactions. Using full-field electromagnetic simulations, we demonstrate numerically how these dielectric antenna arrays can support near-field enhancements in electromagnetic chirality density (the figure of merit for sensing and spectroscopy) within narrow bandwidths (ca. 25 cm^-1). These resonances can be tuned across the full molecular fingerprint region (1500 cm^-1– 500 cm^-1) by scaling the critical dimensions of the antennas to overlap with individual fundamental modes of vibration of chiral molecules. By embedding the high-index antenna arrays within an effective chiral medium model, we show how spectral overlap of molecular resonances with enhanced optical chirality density can increase chiral-optical absorption.

Wednesday, August 28 2019 from 8:30 AM – 8:50 AM, ACS Fall 2019 National Meeting & Exposition, Room 31B (COLL 556), San Diego Convention Center, San Diego, CA, August 25-29 2019.

Tuning Surface Properties in Self-Assembled Monolayers of Multi-Functional Boron Clusters

Dominic P. Goronzy, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

Self-assembled monolayers (SAMs) provide an avenue for creating surfaces with defined chemical and physical properties. We have been interested in an icosahedral cage boron cluster, the carborane, as a building block for SAMs with properties that we can tune to advantage. The carborane has several favorable traits, including variability in the functionalization of the molecule. A thiol group used for surface attachment can be linked to both carbon and boron vertices in the carborane cage. Here, we probed bifunctional carboranes, with both a thiol and a carboxylic acid functional group, which can be at either a para or a meta orientation. The different isomers have distinct dipole moments in orientation and direction. This can lead to the formation of long range dipole-dipole networks within the SAM, which can stabilize the SAM and also modify the local work function of the material. Thus by using one or multiple isomers in the formation of a SAM we can controllably tune the work function. Using STM, we have visualized SAMs composed of two meta carboranethiolate carboxylic acid isomers. Despite the presence of a bulky attachment in the lateral position, these monolayers are relatively pristine and defect free. We probed the chemical behavior of the exposed carboxylic acid group and found that the pKa shifts more alkaline by approximately two pH units. We confirmed that the carboxylic acid is available for reacting with metal ions and organic molecules. This latter trait allowed us to modify the exposed functional group directly on the surface and thereby tune the molecular dipole and alter the local work function. It also enabled us to use chemical liftoff lithography for patterning for further surface modification. Thus, carboranethiolate carboxylic acid SAMs allow us to simultaneous modify multiple material properties.

Wednesday, August 28 2019 from 9:30 AM – 9:50 AM, ACS Fall 2019 National Meeting & Exposition, San Diego Convention Center, Room 31B (COLL 559), San Diego, CA, August 25-29 2019.

Exploration of variables involved in surface pKa shifts of carboxylated carboranethiol self-assembled monolayers

Erin M. Avery, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

Integration of functionalized 2D materials into structured devices requires in-depth understanding of the structure, reactivity, and acid-base properties of the adsorbed molecules at the junction. Self-assembled monolayers (SAMs) have been used extensively to probe and to tune the properties of these interfaces. Alkanethiols or other functionalized alkyl chains with acidic moieties have been used to probe interfacial acid-base behavior. Here, we examine self-assembled monolayers (SAMs) of carboranethiolate molecules functionalized with carboxylic acid groups. Due to the high axial symmetry and robust nature of these molecules, many of the common defects observed n-alkanethiolate monolayers are eliminated symmetry, enabling controlled platforms to study the properties at substrate/environment interfaces. Self-assembled monolayers of carboranethiolates with carboxylic acids attached in the meta position have pK_as ~2 pH units higher on the surface. In this study, we explore the effects of the position of the carboxylic acid functional group and the curvature of the surface on both structure and surface pK_a of the functionalized monolayer. By exploring these different conditions with contact angle titration and scanning tunneling microscopy (STM) we elucidate the roles of environmental conditions and their effects on the underlying mechanisms of surface pK_a shift. We hypothesize that the position of the functional group results in surface pK_a shifts of lesser magnitude the closer it is to the substrate/environment interface. This shift is enhanced with greater curvature of the surface as the acidic moieties become more exposed. This work creates platforms to tailor the acid-base properties of different monolayers in addition to the surface wettability of substrates. This work also has applications in functionalizing surfaces of multilayer devices with solution-processable techniques that have interfaces modulated to control chemical reactivity.

Wednesday, August 28 2019 from 1:00 PM – 1:30 PM, ACS Fall 2019 National Meeting & Exposition, San Diego Ballroom Salon A (ANYL 512), Marriott Marquis San Diego Marina, San Diego, CA, August 25-29 2019.

Aptamer-functionalized microelectrodes and nanopipettes to sense neurotransmitters in neuronal networks

Nako Nakatsuka, Biomedical Engineering, ETH Zürich, Laboratory of Biosensors and Bioelectronics, Zurich, CH, Switzerland

In vitro neuronal networks with defined topology enable investigations into how ensemble network geometries and connectivity affect brain activity. These measurements are not possible in vivo due to the complexity of neuronal processes that cannot be measured sufficiently with current technologies. We have developed strategies to grow neuronal circuits with both structurally and functionally directional connections between neurons using polymeric guidance microstructures on multi-electrode arrays (MEAs). While in vitro MEA recordings of extracellular potentials from spiking neurons is standard practice, simultaneous monitoring of neurochemical signaling has not been possible. Recently, rationally designed oligonucleotide sequences termed aptamers demonstrated specific and selective neurotransmitter recognition in physiological environments. Upon target binding, aptamers undergo conformational changes resulting in the rearrangement of the negatively charged backbone at surfaces. Using this technology, we have developed two new systems for parallel monitoring of neurochemical flux and electrophysiology. In the first approach, we functionalize gold MEAs with aptamers hypothesizing target binding will reversibly alter the surface potential, which can be measured as transient changes in voltage. The second approach is to couple aptamers to the inner surface of quartz nanopipettes (~10 nm tip size) to approach patterned neuronal networks from above. Aptamer conformational changes reversibly gate the diffusion of ions between open and closed states under applied bias potential, resulting in measurable changes in ionic current. Such aptamer-functionalized systems will enable sensing of neurotransmitter flux in localized regions of neuronal networks providing potential insight into the mechanisms underpinning synaptic plasticity.

Wednesday, August 28 2019 from 2:50 PM – 3:10 PM, ACS Fall 2019 National Meeting & Exposition, San Diego, Marriott Grand Ballroom Section 11 (PHYS 368) – Marriott Marquis San Diego Marina, San Diego, CA, August 25-29 2019.

Nanoparticle patterning via chemical lift-off lithography

Naihao Chiang, Leonardo Scarabelli, Gail A. Vinnacombe, Thomas D. Young , Paul S. Weiss, Steven J. Jonas
California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA, United States.
Chemistry and Biochemistry, University of California, Los Angeles, CA, United States.
Department of Pediatrics, David Geffen School of Medicine at the University of California, Los Angeles, Los Angeles, CA, United States.
Eli & Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, CA, United States.
Children’s Discovery and Innovation Institute, University of California, Los Angeles, Los Angeles, CA, United States.

We demonstrate the large-scale patterning of gold nanoparticles (AuNPs) through a scalable, and robust soft lithographic technique named chemical lift-off lithography (Figure 1). Specifically, activated patterned polydimethylsiloxane (PDMS) stamps are placed in conformal contact with a self-assembled monolayer of mercaptoalkanol-functionalized AuNPs. The patterned plasmonic nanostructures generated by “lifting-off” the PDMS exhibit collective optical properties that depend strongly on the design of the pattern. Patterned nanoparticles are readily transferred to other substrates via nanotransfer printing. Overall, the developed approach enables robust fabrication of wafer-scale functional architectures with pre-programmed collective plasmonic properties for applications in lasing, remote sensing, photonic crystals, metamaterials and chiral
plasmonics.

Wednesday, August 28 2019 from 3:55 PM – 4:15 PM, ACS Fall 2019 National Meeting & Exposition, San Diego Ballroom Salon A (ANYL 519) – Marriott Marquis San Diego Marina, San Diego, CA, August 25-29 2019.

Fabrication of wafer-scale metal oxide nanoribbon field-effect transistor biosensors using chemical lift-off lithography

Chuanzhen Zhao, Qingzhou Liu, Kevin M. Cheung, Wenfei Liu, Qing Yang, Xiaobin Xu, Anne M. Andrews, Chongwu Zhou, and Paul S. Weiss

One-dimensional (1D) semiconductor field-effect transistors (FETs), with high surface-to-volume ratios, have been developed as label-free and ultra-sensitive chemical and biological sensors. In this work, we demonstrated a high-throughput and facile cleanroom-free nanolithography method to fabricate large-area and highly-aligned In₂O₃ nanoribbons. Nanoribbon-based FET arrays were constructed over the centimeter scale, which was achieved by a low-temperature sputtering process combined with chemical lift-off lithography. Nanoribbon arrays of 350-nm width, 700-nm pitch, and 20-nm thickness were fabricated, and used as channel materials for FETs. These FETs showed high current on/off ratios >10⁷ in the solid state and good performance in liquid-gating configurations with saturation behavior, low driving voltages, and low leakage currents. Different aspect ratio In₂O₃nanoribbons were fabricated, tested, and compared. The 350-nm nanoribbon FETs show higher pH sensitivity than 20-μm nanoribbons and thin-film FETs. Nanoribbons comprised of In₂O₃ were functionalized with biotin to demonstrate streptavidin detection. Biotin detection at pM levels was achieved using urease enzyme activity as the amplification signal on 350-nm nanoribbon FETs, suggesting the possibility of nanoribbon FETs as platforms for enzyme-based sensing. We explored aptamer-based sensing using nanoribbon FETs where the channel semiconductors were functionalized with highly specific aptamers. Upon binding target molecules, such as the small-molecule neurotransmitter serotonin, target aptamers are hypothesized to alter electric fields near semiconductor surfaces, resulting in conductance changes in FETs. Serotonin-specific aptamer FETs were fabricated, tested, and compared, where 350-nm ribbons showed sensitivities down to fM concentrations for serotonin in high ionic concentration solutions. Wafer-scale In₂O₃nanoribbon transistor biosensors, fabricated by straightforward top-down fabrication processes, were demonstrated as a versitile sensing platform with high sensitivity, including pH, protein-based, and aptamer-based sensing, which are of great interest for next-generation ultra-sensitive biosensor platforms.

Tuesday, August 27 2019 from 10:25 AM – 11:10 AM, ACS Fall 2019 National Meeting & Exposition, Marriott Grand Ballroom Section 8 – Marriott Marquis San Diego Marina, San Diego, CA, August 25-29 2019.

Dimensionality in Surface Functionalization

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Tuesday, August 27 2019 from 5 PM – 7 PM, ACS Fall 2019 National Meeting & Exposition, Grand Ballroom Salons 1 – 4, Marriott Marquis San Diego Marina, San Diego, CA, August 25-29 2019.

Nanoparticle patterning via chemical lift-off lithography

We report a new lipid bilayer-mediated strategy for the detection and enumeration of circulating tumor cells (CTCs) that are shed from a primary tumor site and enter into the bloodstream. Microfluidic devices that integrate nanostructured surfaces have been explored as a promising method for capturing CTCs efficiently. Existing approaches suffer from low capture purity due to clogging and nonspecific cell adhesion, impeding effective translation into routine patient care. To address this issue, we use supported lipid bilayers (SLBs) to prevent the adhesion of nonspecific cells and incorporate biotin-streptavidin conjugated antibodies for the specific detection of CTCs. We use Ewing sarcoma (EWS), an aggressive form of bone and soft tissue tumors with high metastatic potential, as an initial model to test this microfluidic platform. Altogether, this study represents a key step to designing diagnostic tools that incorporate nanostructured, cell-interactive interfaces, which enable high-throughput isolation of EWS-derived CTCs, paving the way for exciting new diagnostic methods that enable “liquid biopsies” for monitoring a patient’s disease status and which can be connected directly to precision medicine analyses to inform therapeutic decisions.

Tuesday, August 27 2019 from 5 pm to 7 pm, ACS Fall 2019 National Meeting & Exposition, Grand Ballroom Salons 1 – 4, Marriott Marquis San Diego Marina, San Diego, CA, August 25-29 2019.

Ultraviolet photoelectron spectroscopy as a probe for spin-selective ionization of chiral molecules: Observing the heavy metal effect in metallized DNA
Dominik Stemer, California NanoSystems Institute and Department of Materials Science and Engineering, UCLA, Los Angeles, CA 90095

The interaction cross-section between spin-polarized electrons and vapor phase chiral molecules is dependent on molecular handedness. This unexpected asymmetry in electron-molecule interactions may contribute to enantiomeric imbalances among biomolecules. High atomic number inclusions in chiral molecules lead to an increase in interaction asymmetries. Films of chiral molecules have been shown to further enhance asymmetries due to molecular orientation effects. This enhancement is manifest as efficient electron spin filtering, even at room temperature. Theoretical models predict that molecular spin-orbit coupling plays a dominant role in spin filtering due to the chiral electrostatic potential, which breaks inversion symmetry as experienced by transmitted electrons, though there is a clear lack of experimental evidence in solid state systems. To test this hypothesis, we design helical DNA molecules that contain mercury ions bound at base-pair mismatches. By controlling the number of mercury atoms along the DNA axis, we are able to manipulate the strength of the helical spin-orbit field via the heavy atom effect. We form self-assembled monolayers of mercurated DNA on ferromagnetic substrates with perpendicular magnetic anisotropy. Using ultraviolet photoemission spectroscopy, we are able to measure magnetization-dependent photoionization energies arising from asymmetric interactions between low-energy photoelectrons and oriented DNA molecules. We note an enhancement and inversion in spin selectivity upon mercury inclusion, suggesting that heavy-metal doping may be a practical means toward its manipulation. Demonstrating control over molecular spin- orbit coupling to tune spin selectivity in chiral molecules is critical to assess their practicality for organic spintronics applications, and to investigate their role in the evolution of enantiospecificity within biomolecules.

Tuesday, August 27 2019 from 5 PM – 7 PM, ACS Fall 2019 National Meeting & Exposition, Grand Ballroom Salons 1 – 4, Marriott Marquis San Diego Marina, San Diego, CA, August 25-29 2019.

Poster: Supported lipid bilayer coated microfluidic device for capturing circulating tumor cells

Lisa M. Kawakami, California NanoSystems Institute and Department of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

Monday, August 26 2019 from 8:05 AM – 8:25 AM, ACS Fall 2019 National Meeting & Exposition, San Diego Torrey Pines 3 (ANYL 277) – Marriott Marquis San Diego Marina, San Diego, CA, August 25-29 2019.

Advances in chemical lift-off lithography

Kevin M. Cheung, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

Chemical lift-off lithography (CLL) is a subtractive soft-lithographic technique used to pattern self-assembled monolayers (SAMs) containing functional alkanethiolates on gold surfaces. Alkanthiolate molecules, along with a single monolayer of gold, are removed in this process by oxygen-plasma activated polydimethysiloxane (PDMS) stamps. Monolayers patterned via CLL are robust, in contrast to conventional soft-lithography, enabling high-fidelity patterning over a dynamic range of feature sizes (millimeter to nanometer). This process has a wide range of applications, including patterning of bioactive molecules and supported gold monolayers, as well as the simple, convenient fabrication of field-effect transistors. Recently, we have advanced CLL to pattern additional surfaces, including other coinage metals (e.g., Pt, Pd, Ag, Cu), reactive transition metals (e.g., Ni, Ti, Al), and semiconductors (e.g., Ge). In all cases, high-fidelity patterns were achieved. X-ray photoelectron spectroscopy analysis of PDMS stamps post-CLL revealed lift-off of corresponding metals, demonstrating that (mono)layers of metal atoms, along with alkanethiolates, were removed in the process. Changing SAM compositions is another avenue of technique development that affects the CLL process. By using bifunctional cage molecules (i.e., isomers of carboxylic-acid-functionalized carboranethiolates), which form more pristine and defect-free monolayers, in comparison to conventional alkanethiolates, we increase the yield of molecules removed by CLL. We hypothesize that this improvement in yield corresponds to differences in the Au-S binding strengths of the SAM component molecules. Patterning of different carboranethiolate isomers that are functionally identical, but with dipole moments of different magnitude and direction, will enable tuning of the local substrate work function in patterned regions. These advances in metal and semiconductor patterning using CLL demonstrate the versatility of CLL in high-resolution, high-throughput, low-cost fabrication, and for tailoring interfacial surface interactions towards creating precise chemical, physical, and electronic nanoscale contacts.

Monday, August 26 2019 from 4:15 PM – 4:30 PM, ACS Fall 2019 National Meeting & Exposition, San Diego Ballroom Salon A (ANYL 361) – Marriott Marquis San Diego Marina, San Diego, CA, August 25-29 2019.

Implantable aptamer field-effect transistor neuroprobes: Towards in vivo neurotransmitter detection

Chuanzhen Zhao, I-Wen Huang, Kevin M. Cheung, Nako Nakatsuka, Hongyan Yang, Leonardo Scarabelli, Liv K. Heidenreich, Jason Belling, Paul S. Weiss, Harold G. Monbouquette, and Anne M. Andrews

Monitoring neurotransmitters in vivo necessitates sensors that approach the spatiotemporal resolution of neuronal communication, while differentiating similarly structured neurochemicals with high selectivity. We have developed biosensors based on nucleic-acid aptamers, coupled to ultrathin In₂O₃ (~3-nm) field-effect transistors (FETs). These biosensors show high sensitivity and selectivity for serotonin and dopamine with fM detection limits in vitro. To enable in vivo measurements, we miniaturized our sensor architecture to fabricate neuroprobes with arrays of aptamer-field-effect transistors. The initial prototype for an implantable microprobe is fabricated using micro-electro-mechanical systems (MEMS) technologies on Si (150-μm thick). Each neuroprobe has lithographically patterned interdigitated gold electrodes deposited atop ultrathin, semiconducting In₂O₃channels, with a shank width and thickness of 150 μm. Functionalization of the exposed semiconducting surfaces with neurotransmitter-specific aptamers facilitated electronic neurotransmitter sensing. Miniaturization of individual FETs leads to increases in the number of independent transistors on a single neuroprobe for multi-site/multi-target detection capabilities. We characterized target sensitivity ranges, detection limits, and sensor stabilities in vitro prior to conducting in vivo measurements. We assessed biofouling of neuroprobes by performing ex vivo measurements in brain tissue homogenates. We also fabricated flexible neuroprobes using polyimide as a substrate instead of rigid Si to reduce immunological responses. Implantable aptamer-field-effect transistor-neuroprobes, including additional designs on flexible substrates, will enable in vivo detection of neurotransmitters in the brain with high spatial resolution and selectivity.

Monday, August 26 2019 from 8 PM – 10 PM, ACS Fall 2019 National Meeting & Exposition, Exhibit Hall B (COLL 172), San Diego Convention Center, San Diego, CA, August 25-29 2019.

Poster: Supported lipid bilayer coated microfluidic device for capturing circulating tumor cells

Lisa M. Kawakami, California NanoSystems Institute and Department of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

Sunday, August 25 2019 from 5:30 PM – 7:30 PM, ACS Fall 2019 National Meeting & Exposition, Exhibit Hall DE, San Diego Convention Center, San Diego, CA, August 25-29 2019.

Poster: Supported lipid bilayer coated microfluidic device for capturing circulating tumor cells

Lisa M. Kawakami, California NanoSystems Institute and Department of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

Sunday, August 25 2019 from 3:50 PM – 4:10 PM, ACS Fall 2019 National Meeting & Exposition, San Diego Room 30E – San Diego Convention Center, San Diego, CA, August 25-29 2019.

Soft-release of captured cells via plasmonic gold nanostars

Gail A. Vinnacombe,^a,b Naihao Chiang,^a,b Liv K. Heidenreich,^a,b Yuan Hu,^c Isaura Frost,^a,b Derek T. Inouye,^a,b Yao Gong,^a,b Timothy S. Fisher,^c Leonardo Scarabelli,^a,b Paul S. Weiss^a,b & Steven J. Jonas^c,d

^aDepartment of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States

^bCalifornia NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, United States

^cSamueli School of Engineering, University of California Los Angeles, Los Angeles California 90095, United States

^dEli & Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, California 90095, United States

^eChildren’s Discovery and Innovation Institute, University of California, Los Angeles, Los Angeles, California 90095, United States

Gold nanostars (AuNSTs) are ideal for integration with microfluidic technologies targeting biological applications due to their shape, high surface area, extinction in the near-infrared, and biocompatibility. We have developed a robust and simple microfluidic method for the direct growth of anisotropic AuNSTs on the internal walls of glass microcapillaries with high surface density and uniformity. The synthesis was optimized to yield AuNSTs with high anisotropy and surface area for optimal light-to-heat conversion upon laser irradiation. The temperature generated within a AuNST-modified microfluidic capillary was measured at variable laser power and in “flow” and “no-flow” conditions, where we found that heat generation is more localized under flow conditions and can be further controlled with varying laser power. Additionally, we performed simultaneous measurement of capillary temperature and surface-enhanced Raman spectroscopy (SERS) of molecules bound to the AuNSTs, which enabled correlation of macroscale heating with the nanoscale environment. Finally, the capability of the platform for controlled localized heating was used to explore hyperthermia-assisted detachment of cells adhered to the capillary walls. Ultimately, the primary goal of this work will be to apply these devices for cell-sorting applications, such as cancer cell isolation from blood.

Thursday, August 22 2019 from 10:50 – 11:30 PM, Methods & Applications in Fluorescence, UCSD Price Center East – East Ballroom, San Diego, CA, August 20-24 2019.

Submolecular resolution spectroscopic imaging for photoactive molecules and assemblies

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We have developed and applied new multimodal nanoscale analysis tools based on the scanning tunneling microscope (STM) to measure structure, function, and spectra simultaneously.^1-5 We are particularly interested in the interactions of photons with precisely assembled structures.^1-4 We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures with controlled environments and dimensionality, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules and assemblies.^1,2,4,6 The measured results of photoexcitation include photoconductivity, regioselective reaction, intramolecular charge redistribution, and environmental sensitivity.^1-5 We apply this method to optimize molecules and materials for energy conversion and storage. Concepts from sparsity and compressive sensing are developed and applied to guide efficient data acquisition and to accelerate data analysis and information assembly.

Tuesday, August 20 2019 from 11 – 11:30 AM, 4th International Symposium for Chinese American Society of Nanomedicine and NanoBioTechnology (CASNN),Conference Hall, Zhejiang University, Xiaoshan District, Hangzhou, China, August 20-22 2019.

Adding the Chemical Dimension to Lithography at all Scales: Enabling Cellular Therapies

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Sunday, August 18 2019 from 3:30 – 4:00 PM, ChinaNano 2019, Convention Hall 2-B, Beijing Continental Grand Hotel Beijing, China, August 17-19 2019.

Friday, August 16 2019 from 3:30 – 5:30 PM (8 Minute Talk), The Directors’ Forum on Nanotechnology, Room 307 Beijing International Convention Center, Beijing, China.

Taking on Global Challenges in Science, Engineering, Medicine, & Society

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Thursday, August 15 2019 from 2:00 PM – 5:00 PM 2019 UCLA SPUR Poster Symposium, NRB 132 Auditorium, University of California, Los Angeles, Los Angeles, CA, August 15 2019.

Poster: Effective capture of ewing sarcoma circulating tumor cells using supported lipid bilayer
Esteban Bautista, California NanoSystems Institute and Department of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

Circulating tumor cells (CTCs) shed from primary tumors and enter into the vascular or lymphatic systems. These circulating cells can provide valuable diagnostic information and have great potential for disease monitoring and testing personalized therapies for cancer. The isolation of CTCs is challenging due to their rare numbers (1 in ~10⁹ blood cells) and their low recovery using existing purification techniques. In particular, enumeration of CTCs derived from Ewing Sarcoma (EWS), an aggressive type of bone or soft tissue malignancy and the second most common bone tumor in children and adolescents, is particularly challenging. The aim of this study is to develop and to test microfluidic devices that use antibody-functionalized nanopillars coated with supported lipid bilayers (SLBs) to capture Ewing Sarcoma-derived CTCs.Selective capture of the CTCs is accomplished by 1) incorporating nanopillar structures on silicon surfaces to increase the surface-area-to-volume ratio and to restrict the mobility of cells promoting cell interactions; 2) integration of a chaotic mixer that induces microvortex mixing in order to increase the probability of cell-surface interactions; and 3) functionalization of the nanostructures with supported lipid bilayers (SLBs) that incorporate antibodies specific to leucine-rich repeat and an Ig domain-containing protein 1 (LINGO1), a cell-surface protein that has been identified in over 90% of EWS tumor cells.

2019 CSST Seminar, Department of Chemistry, CHS 23-105, UCLA, August 6 2019.

Opportunities in Science, Engineering, & Medicine: The View from Below

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

University of Hong Kong, Department of Chemistry, Hong Kong, July 26 2019.

Thursday July 25 2019 from 9:00 AM – 9:40 AM, 2019 IEEE 19th International Conference on Nanotechnology (IEEE-NANO), The Parisian Macao, Room 7201, Macau SAR, China, July 22-26 2019.

Monday 15 July 2019, 12:00 PM, Amgen Scholars Faculty Research Talk, Life Science Building 2320, UCLA, Los Angeles California.

Adding the Chemical Dimension to Lithography at All Scales: Enabling Cellular Therapies & Other Adventures in Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Friday 12 July 2019, 10:20 AM, C-MIT Workshop: Micro- and Nanotechnologies for Medicine Emerging Frontiers and Applications, Mong’s Learning Center – Engineering VI, 404 Westwood Blvd, Los Angeles California, July 8-12 2019.

Adding the Chemical Dimension to Lithography at All Scales: Enabling Cellular Therapies & Other Adventures in Biology and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Thursday 11 July 2019, 11:40 AM, C-MIT Workshop: Micro- and Nanotechnologies for Medicine Emerging Frontiers and Applications, Mong’s Learning Center – Engineering VI, 404 Westwood Blvd, Los Angeles California, July 8-12 2019.

Implantable Aptamer Field-Effect Transistor Neuroprobes: Towards in Vivo Neurotransmitter Detection

Chuanzhen Zhao, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

Monitoring neurotransmitters in living tissue necessitates sensors that approach the spatiotemporal resolution of neuronal communication, while differentiating similarly structured neurochemicals with high selectivity. We have engineered sensors based on chemically synthesized oligonucleotide receptors, termed aptamers, coupled to field-effect transistors (FETs) for fully electronic sensing. These sensors show high sensitivity and selectivity for neurotransmitters and other small molecules with femtomolar detection limits in vitro. To enable in vivo measurements, we miniaturized sensor architectures to microfabricate neuroprobes with arrays of aptamer-field-effect transistors. The initial prototype is microfabricated on silicon. Each device has lithographically patterned interdigitated gold source and drain electrodes deposited on ultrathin, semiconducting indium oxide channels. Functionalization of semiconducting surfaces with neurotransmitter-specific aptamers enabled electronic neurotransmitter sensing. Reducing individual FET footprints leads to increases in the numbers of independent transistors on a single neuroprobe for multi-site/multi-target detection capabilities. Individual FETs are electrically addressable for multiplexed aptamer functionalization. Silicon microprobes can be fabricated to include electrophysiological sensors, and optical and chemical stimulation for multimodal function. Prototypes of next generation designs on flexible substrates have been fabricated on thin polyimide. Neuroprobes will enable in vivo detection of neurotransmitters in the brain with high spatial resolution and selectivity.

Gordon Research Seminar: Spin Dynamics and Transport: From Single-Domains to Textures, Eurotel Victoria, Les Diablerets, Switzerland, July 6-7 2019.

Elucidating Spin-Dependent Ionization in Photoemission from Chiral Molecular Films

John M. Abendroth, Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305

Chiral molecules are capable of filtering transmitted electrons based on spin at room-temperature. Recently, we showed that enantioselective and spin-dependent interactions between photoelectrons and chiral alpha-helical peptides assembled on ferromagnetic substrates are physically manifested as differences in photoionization energies – an indirect effect hypothesized to be attributed to helicity-dependent molecular ionization cross sections by photoelectron impact. We are continuing systematic experimental investigations of contributing mechanisms to spin polarization in over-the-barrier photoelectron transmission by the chiral-induced spin selectivity effect. Molecular spin–orbit coupling is thought to play a major role due to the chiral electrostatic potential experienced by transmitted electrons. To test this prediction, we designed helical DNA molecules that contain mercury ions bound specifically at base-pair mismatches. We manipulate the helical handedness, dipole orientation, and strength of the helical spin-orbit field via the heavy atom effect by controlling the number and position of mercury ions along the DNA axes. Self-assembled monolayers of mercurated DNA on ferromagnetic substrates that are magnetized up vs down are analyzed by ultraviolet photoelectron spectroscopy. We measured larger magnetization-dependent differences in photoionization energies of mercurated DNA helices compared to assemblies sans mercury ions, as well as a reversal of spin selectivity upon inversion of helical handedness. Current work is aimed at investigating further the influence of heavy ion incorporation on molecular spin-orbit coupling to tune and to enhance spin selectivity by chiral molecular assemblies, and to assess critically their practically for spintronics applications.

Saturday 22 June 2019, NanoMedicine, Taipei, Taiwan

Nanotechnology Approaches to Biological Heterogeneity and Cellular Therapies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

The great promise of single-molecule/assembly measurements is to understand how critical variations in structure, conformation, and environment relate to and control function. New approaches to sensing, imaging, and analysis are keys to elucidating these associations. I will discuss current and upcoming advances and will pose the challenges that lie ahead in creating, developing, and applying new tools for biology and medicine. These advances include using biomolecular recognition in sensor arrays to probe dynamic chemistry in the brain and microbiome systems. It also includes fusing spectroscopic imaging modalities and freeing up bandwidth in measurements to record simultaneous data streams and to expand our dynamic range. Recent advances in sparsity and compressive sensing can be applied both to new analysis methods and to directing measurements so as to assemble and to converge structural and functional information. Early examples will be discussed. Further, we introduce biomolecular payloads into cells for gene editing at high throughput for off-the-shelf solutions targeting hemoglobinopathies, immune diseases, and cancers. We circumvent the need for viral transfection and electroporation, both of which have significant disadvantages in safety, throughput, cell viability, and cost. Mechanical deformation can make cell membranes transiently porous and enable gene-editing payloads to enter cells. These methods use specific chemical functionalization and control of surface contact and adhesion in microfluidic channels.

Friday 21 June 2019, Nano-gene Therapy and Regenerative Medicine Summit, Taipei, Taiwan

6th Nano Today Conference, Lisbon, Portugal, June 16-20 2019.

Thursday 13 June 2019 (8:30 AM – 9:15 AM), 2nd Cellular Therapies Symposium, David Geffen auditorium: Geffen Hall 130, UCLA, Los Angeles, California

Cellular Bioengineering
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Thursday 6 June 2019, UCLA/USC/Caltech Postdoc Research Symposium, CNSI UCLA, Los Angeles, California

Monday 27 May 2019, Spanish Society of Chemistry Biennial Meeting, San Sebastian, Spain, May 2019. Keynote.

Friday 24 May 2019, CIC nanoGUNE, San Sebastian, Spain

Atomically Precise Chemical, Physical, and Electronic Nanoscale Contacts
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

The physical, electronic, mechanical, and chemical connections that materials make to one another and to the outside world are critical. Just as the properties and applications of conventional semiconductor devices depend on these contacts, so do nanomaterials, many nanoscale measurements, and devices of the future. We discuss the important roles that these contacts can play in preserving key transport and other properties via optimized transmission and robustness. Measurements of nanoscale connections from a number of perspectives guide the path to future opportunities and challenges, as well as the need for new nanoscale tools. Band alignment and minimally disruptive connections are both targets and can be characterized in both experiment and theory. Once targets are identified for both components and contacts, precursors can be designed to produce functional, connected materials.

Thursday 23 May 2019, CIC biomaGUNE, San Sebastian, Spain

Tuesday 21 May 2019, Research Poster Day, Pauley Pavilion, UCLA, Los Angeles, California

Spin Selectivity in Chiral Molecules and Its Role in Enantioselective Processes
Matthew Ye, California NanoSystems Institute and Department of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

Chiral induced spin selectivity (CISS) refers to the preferred transmission of electrons of certain spin through chiral molecules over electrons of the opposite spin. This phenomenon is particularly pronounced in DNA due to its helical geometry. In our work, we have shown that the spin selectivity of DNA can be manipulated by tuning molecular spin-orbit coupling via insertion of heavy metal ions into the base stack. Motivated by these mechanistic insights, we proceeded to explore how the CISS effect is manifested in chemical and biological systems. Recently, it has been hypothesized that spontaneous spin polarization in interacting chiral molecules may be responsible for the enantioselectivity of certain chemical reactions. We describe a system that allows this hypothesis to be tested experimentally. A self-assembled monolayer of an achiral molecule is formed on a ferromagnetic substrate and a meso compound is allowed to react with it. If CISS plays a role in enantioselectivity, the meso compound will prefer to react in one orientation over the other depending on the direction in which the substrate is magnetized. These findings may contribute to our understanding of intermolecular interactions by determining whether the strength of these interactions is influenced not only by charge, but also by spin.

Frontiers of Translational Materials Science, Paiknam Academic Information Center and Library, Hanyang University, Seoul, Korea, Thursday 17 – Friday 18 May 2019

New Dimensions in Patterning: Placement and Metrology of Chemical Functionality at All Scales

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

We place single molecules and assemblies into precisely controlled environments on surfaces. The inserted assemblies and the monolayer matrices that contain them can be designed so as to interact directly, to give stability or other properties to functional supramolecular assemblies. New families of highly symmetric molecules are being developed to yield even greater control and are enabling elucidation of the key design parameters of both the molecules and assemblies. These design elements, in turn, enable controlled chemical patterning from the sub-nanometer to the centimeter scales. We simultaneously develop metrology tools for these methods to give unprecedented insight on the structures, function, and properties of these assemblies.

Thursday 16 May 2019 (10:50 AM), BioChips, Seoul, Korea

Advances in Nanotechnology Approaches Measuring Chemical Signaling Molecules and High-Throughput Gene Editing

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Bioengineering, and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Thursday 16 May 2019 (1:30 PM), KCAP Sogang University, Mini-symposium on the Nanostructured Materials , P. S. Weiss, Seoul, Korea

Friday 10 May 2019, Student Exit Seminar, Young Hall 2033, UCLA, Los Angeles, California

Interfacial Chemistry of Liquid Metal: Eutectic Gallium Indium (E-GaIn)

Logan A. Stewart, Department of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095
Gallium-based liquid metal alloys have garnered attention for their use in self-healing and flexible electronics, soft robotics, catalysis, and biomedicine. Advances in these next-generation materials have only been made possible through understanding of the liquid-metal/X interfaces, where X represents some immiscible gas/liquid/solid. We propose that liquid metal chemistry of gallium and gallium-based alloys can be subdivided into a series of interfacial phenomenon that all harness the ‘skin’ comprised of the metal atoms occupying the liquid-metal surface. We first consider the oxidation of liquid metal in air. Room-temperature liquid metals, their interactions in air, and the kinetics of oxidation are a critical first step towards understanding material properties of liquid metals such as the surface-energy/surface-tension that originates at the oxide interface. Once understood, this oxidation can be prevented via surface-bound ligands. We employed gallium-thiol chemistry and bi-functional thiol molecules as capping ligands for the surface stabilization of gallium-based liquid metal nanostructures. These surface stabilization effects, within the parameter of mixtures of both polar and nonpolar solvents, are examined as a new type of emulsified system. The kinetic behavior of these liquid gallium alloys and the atomic species dissolved within these liquid metal alloys can act both as a regenerative reaction interface and a barrier for controlled reaction kinetics. Further, the liquid-liquid mixing of bi-phasic liquid metal composites and materials are explored to understand ‘metalophilicity’. Traditionally, hydrophilicity has been employed in the understanding of the wetting properties of materials. However, we show how surface tension and the stabilization of surface-bound metal oxides presents a roadmap towards understanding the matter-matter interactions within liquid-metal/X composite materials.

Thursday 9 May 2019, Student Exit Seminar, Young Hall 2033, UCLA, Los Angeles, California

Intermolecular Interactions and Surface Properties in Self-Assembled Monolayers of Functional Boron Clusters

Dominic P. Goronzy, California NanoSystems Institute and Department of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

Self-assembled monolayers (SAMs) are an advantageous platform for probing the fundamental interactions that dictate the spontaneous formation of nanostructures and supramolecular assemblies and directly affect macroscale properties. As such, SAMs provide an avenue for creating surfaces with defined chemical and physical properties. The assembly of these nanoscale constructs is driven by three primary factors: the interface between the substrate and the monolayer, the interactions between the adsorbate molecules, and the interface between the monolayer and the environment. We study an icosahedral cage boron cluster, the carborane, as a building block for SAMs with properties that we can tune to advantage. Carboranes have several favorable traits, including providing a scaffold for a variety of functional groups. A chalcogenide group, typically a thiol, is used for surface attachment; moreover, bifunctional carboranes also enable control of the valency during assembly and greater reactivity at the environmental interface of the SAM. Additionally, isomers of carboranethiol have distinct dipole moments in terms of orientation and magnitude. The dipoles can lead to the formation of long-range dipole‑dipole networks within the SAM, which can stabilize the SAM and also modify the surface properties of the material. The rigid, symmetric backbone of the carborane cage results in SAMs that are relatively pristine and defect free. Due to these advantageous traits, carboranes enable us to create monolayers with tunable interactions at the SAM interfaces. This system not only enables us to study the molecular forces of assembly but also facilities the simultaneous modification of both chemical and physical properties of surfaces and interfaces.

Wednesday 1 May 2019,Perimeter Institute Lecture, Waterloo, Ontario, Canada

Nanotechnology Meets Neuroscience and Medicine

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Anne M. Andrews, Psychiatry and Biobehavioral Sciences and Department of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

To make progress on serious problems in biology and medicine takes a combination of skills, tools, and approaches, some of which have to be developed along the way. A key aspect of this effort is learning to communicate across fields to identify the scientific targets and then the existing technologies that will be needed and importantly those new tools that need to be invented. We describe our motivation for eavesdropping on intercellular chemical signaling in the brain, because the brain is not a computer in the way that our current devices function. We have guided advances in nanotechnology to take on this and other grand challenges in biology and medicine. Along the way, we are training new generations of students, staff, and colleagues to look across fields to identify and to target significant problems and to have the communication skills to address them.

To make progress on serious problems in biology and medicine takes a combination of skills, tools, and approaches, often requiring collaboration across seemingly disparate fields. The trick to making breakthroughs often lies in learning to communicate across disciplines to identify existing technologies – and, crucially, the new tools that need to be invented.

Anne M. Andrews is a neuroscientist whose work eavesdrops on chemical signaling in the brain. Paul S. Weiss is a nanoscientist who studies materials at the smallest scales. Their scientific collaboration began by advancing nanotechnology to pursue grand challenges in neuroscience bridging their two fields. This expansion of each of their efforts led to ongoing advances in biology and medicine.

In a special joint public lecture, Andrews and Weiss will describe their motivation and explain how they are training new generations of students and fellow researchers to look beyond traditional academic boundaries to target significant problems and to develop the necessary communication skills to address them.

Tuesday April 30 2019 (2:00 PM – 3:00 PM) Waterloo Institute for Nanotechnology (WIN), Distinguished Lecturer, Waterloo, Ontario, Canada

Precise Chemical, Physical, and Electronic Nanoscale Contacts
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Friday 26 April,1st Annual Conference of Chinese Society for Nanobiology and Xiong’an Forum on Innovative Nanomedicine, Baoding, China, Wednesday 24 April – Monday 29 April 2019

Adding the Chemical Dimension to Lithography at All Scales: Enabling Cellular Therapies and Studies in Chemical Signaling
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

The great promise of single-molecule/assembly measurements is to understand how critical variations in structure, conformation, and environment relate to and control function. New approaches to sensing, imaging, and analysis are keys to elucidating these associations. I will discuss current and upcoming advances and will pose the challenges that lie ahead in creating, developing, and applying new tools for biology and medicine [1-3]. These advances include using biomolecular recognition in sensor arrays to probe dynamic chemistry in the brain and microbiome systems. It also includes fusing spectroscopic imaging modalities and freeing up bandwidth in measurements to record simultaneous data streams and to expand our dynamic range. Recent advances in sparsity and compressive sensing can be applied both to new analysis methods and to directing measurements so as to assemble and to converge structural and functional information. Early examples will be discussed. Further, we introduce biomolecular payloads into cells for gene editing at high throughput for off-the-shelf solutions targeting hemoglobinopathies, immune diseases, and cancers. We circumvent the need for viral transfection and electroporation, both of which have significant disadvantages in safety, throughput, cell viability, and cost. Mechanical deformation can make cell membranes transiently porous and enable gene-editing payloads to enter cells. These methods use specific chemical functionalization and control of surface contact and adhesion in microfluidic channels.

Tuesday 23 April 2019 (11:10 AM – 12:00 PM) Organic Chemistry Seminar, UC Berkeley, Berkeley, CA

Thursday 11 April 2019, University College Dublin

Nanotechnology Approaches to Biological Heterogeneity and Cellular Therapies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Tuesday 9 April 2019, Distinguished Speaker Seminar at the University at Buffalo, Buffalo, New York

Precise Chemical, Physical, and Electronic Nanoscale Contacts

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Thursday 4 April 2019, Frontiers Lecture at Case Western Reserve University, Cleveland, Ohio

Nanoscience, Nanotechnology, and Beyond

Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Wednesday 3 – Thursday 4 April 2019, Aptamers 2019 Oxford at St. Hilda’s College, Oxford, UK

Development of Aptamer-Field-Effect Transistor Sensors: Towards Point-of-Care

Kevin M. Cheung, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

Thursday 28 March 2019, Les Shemilt Lectureship, McMasters University, Hamilton, ON

Tuesday 26 March 2019, University of Alberta, Edward Herbert Boomer Memorial Lecture, Canada, Monday 25 March – Wednesday 27 March 2019

Monday 25 March 2019, University of Alberta, Edward Herbert Boomer Memorial Lecture, Canada, Monday 25 March – Wednesday 27 March 2019

Nanotechnology Approaches to Biological Heterogeneity and Cellular Therapies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Friday 22 March 2019, 4:30 PM – 6:30 PM, 9th International IEEE EMBS Conference On Neural Engineering, Hilton San Francisco Union Square Hotel, San Francisco, CA, Wednesday 20 March – Saturday 23 March 2019

Poster: Aptamer Field-Effect Transistor Neuroprobes: Towards in Vivo Neurotransmitter Detection
Chuanzhen Zhao, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

Implantable aptamer-functionalized field-effect transistor (FET) neuroprobes were developed for in vivo neurotransmitter monitoring. Indium oxide (In2O3) semiconductor-based FETs were coupled with synthetic oligonucleotide receptors, termed aptamers, to monitor neurotransmitters, such as serotonin or dopamine, with nanomolar to femtomolar detection limits. Silicon-based implantable neuroprobes patterned with FETs having individual widths of ca. 150 μm were fabricated. We analyzed neuroprobe sensitivity ranges, detection limits, selectivity, and biofouling properties in brain tissue homogenates. Implantable aptamer-FET neuroprobes will enable in vivo detection of neurotransmitters in the brain with high sensitivity and selectivity.

Tuesday February 26 2019 (5:00 PM – 7:00 PM), Grad Slam, University of California, Los Angeles, CA

Nanotechnology for Early Stage Cancer Detection

Lisa Kawakami, Department of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

Tuesday 19 February 2019, Chemistry Seminar, Claremont Colleges, Claremont, California

Friday, February 1 2019 (11:50 AM – 1:30 PM), Broad Stem Cell Research Center Conference, University of California, Los Angeles, CA

Poster Presentation: Slippery liquid-infused porous surfaces (SLIPS) for cell deformation enabling intracellular cargo delivery
Isaura Frost, Department of Bioengineering and Medical Scientist Training Program at David Geffen School of Medicine, UCLA, Los Angeles, CA 90095

Abstract: Intracellular delivery technologies that are scalable, cost-effective, and efficient are required to process large populations of stem cells more effectively into gene and cellular therapy products for patient care. Microfluidic devices that leverage cellular membrane deformation to render cells transiently porous as cells pass through narrow microchannels are currently hindered by issues with clogging that leads to device failure within minutes. We are developing and testing a straightforward deformation technique that consists of passing cells through the pores of slippery liquid-infused porous surface (SLIPS)-modified polytetrafluoroethylene (PTFE) cell culture inserts by application of negative pressure. Delivery of green fluorescent protein (GFP) expression plasmids with transfection efficiencies comparable to available commercial technologies (i.e., lipofection and electroporation) is demonstrated. In parallel, we are developing and testing SLIPS-based microfluidic devices with anti-fouling properties. These bioinspired omniphobic coatings avoid biofouling issues that have precluded existing technologies to enable rapid and sustainable transport of biomolecular payloads to target stem cell populations. These good manufacturing practice (GMP)-compatible, table-top approaches do not require specialized equipment, viral vectors, or reagents, offering a versatile simple engineering solution for manufacturing future stem cell-based gene and cellular therapies.

Monday, January 28 2019 (9 AM – 12 PM), Symposium on Chemical Reaction Dynamics, IAMS SAB, Taipei, Taiwan January 20-28 2019

Targeting Precise Chemical, Physical, and Electronic Nanoscale Contacts by Reaction Design
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Tuesday, January 22 2019 (4 PM – 5 PM), Cha-Bio Forum, Seongnam, South Korea, January 22 2019

Opportunities for Nanotechnology in Biology and Medicine
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Sunday, January 20 2019 (4 PM – 5 PM Tutorial – 1), 5th Muju International Winter School Series, Muju Winter School, Muju-gun, South Korea, January 18 – 22 2019

Monday, January 14 2019 (5:45pm), UCLA-Caltech MSTP tutorial series (154 BSRB), UCLA, Los Angeles, California January 14 2019

Nanotechnology Approaches to Cellular Therapies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

We introduce biomolecular payloads into cells for gene editing at high throughput for off-the-shelf solutions targeting hemoglobinopathies, immune diseases, and cancers. We circumvent the need for viral transfection and electroporation, both of which have significant disadvantages in safety, throughput, cell viability, and cost. Mechanical deformation can make cell membranes transiently porous and enable gene-editing payloads to enter cells. These methods use specific chemical functionalization and control of surface contact and adhesion in microfluidic channels. Likewise, penetration of reproducibly nanomanufactured, loaded sharp features can introduce these packages into individual or many cells. We discuss our progress with these approaches and the methods that we use to quantify success.

Monday 10 December 2018, National Center for Nanoscience and Technology, Beijing, China, December 10 2018

Nanotechnology Approaches to Biological Heterogeneity and Cellular Therapies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Friday 7 December 2018 (9:00 AM – 9:30 AM), Precision Medicine, Bengbu, Anhui Province, China, December 7-9 2018

Nanotechnology Approaches to Biological Heterogeneity and Cellular Therapies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Friday 30 November 2018 (2:00 PM – 2:30 PM) ACS on Campus University of Manchester, Manchester, England, November 30 2018

Wednesday 28 November 2018 (5:00 PM – 6:00 PM) ACS on Campus University of Durham, Durham, England, November 28 2018

Monday 26 November 2018 (3:30 PM – 4:30 PM) School of Engineering Keynote, Ashworth Labs – Lecture Theatre 3, Edinburgh University, Edinburgh, Scotland, November 26 2018

Nanotechnology Approaches to Biological Heterogeneity and Cellular Therapies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Thursday 15 November 2018 (7:00 PM – 9:00 PM)
Andrea Polli’s – Hacking the Grid, CNSI Presentation Space (South), UCLA, Los Angeles, California, November 15 2018

Andrea Polli’s project Hacking the Grid, reveals how photography, digital imagery, and data visualizations can inspire community activism and political action. Polli is an artist working at the intersection of art, science, and technology. For Hack the Grid, she presents past and current projects that reveal how data visualizations create emotional impact and societal change. Polli also engages in conversations with scientists, activists, technologists, and designers in Pittsburgh, a city at the intersection of technological advancements and longstanding ecological concerns.

Saturday November 10 (12:00 – 1:00 PM, 2:50 – 3:35 PM) 2018 Glenn T. Seaborg Symposium, CNSI, UCLA
Large-area ultrathin metal-oxide semiconductor nanoribbon arrays and aptamer field-effect transistor biosensors fabricated by chemical lift-off lithography

Chuanzhen Zhao_,Xiaobin Xu, Wenfei Liu, Kevin M. Cheung, Nako Nakatsuka, Sang-Hoon Bae, Qing Yang, Jason N. Belling, You Seung Rim, Yang Yang, Milan Stojanovic, Anne M. Andrews, and Paul S. Weiss

(1) California NanoSystems Institute; (2) Department of Chemistry & Biochemistry; (3) Department of Materials Science and Engineering, UCLA, Los Angeles, CA 90095, USA; (4) School of Intelligent Mechatronics Engineering, Sejong University, Seoul 05006, Republic of Korea; (5) Division of Experimental Therapeutics, Department of Medicine, Department of Biomedical Engineering, Columbia University, New York, New York 10032, USA; (6) Department of Psychiatry and Biobehavioral Health, Semel Institute for Neuroscience and Human Behavior, and Hatos Center for Neuropharmacology, UCLA, Los Angeles, CA 90095, USA

One-dimensional nanostructure-based field-effect transistors (FETs), such as nanoribbon and nanowire FETs, are of great importance to the development of highly sensitive chemical and biological sensors because of their high surface-to-volume ratios. Challenges remain within conventional nanofabrication techniques, such as high cost and low throughput, which hinders the widespread application of these nanoelectronics and biosensors. In this work, we demonstrated a high-throughput nanolithographic method to fabricate ultrathin (~3 nm) In₂O₃nanoribbon arrays, and constructed nanoribbon-based FETs on the wafer scale, using a sol-gel process followed by chemical lift-off lithography, a subtractive soft lithographic technique developed by our groups. Nanoribbon arrays of 200‑nm width and 400‑nm pitch were fabricated and then used as a channel material for FETs, which showed current on/off ratios of over 10⁷and a peak mobility of ~13.7 cm² V^-1 s^-1. Field-effect transistors with ultrathin In₂O₃channels were then explored as highly selective neurotransmitter sensors, where the channel was functionalized with oligonucleotide stem-loop receptors, termed aptamers, which were selected for the adaptive recognition of neurotransmitter targets. Upon binding of neurotransmitters, such as serotonin, aptamers with negatively charged backbones are hypothesized to change the electric potential of the semiconducting channel through their conformational changes. Nanoribbon-based serotonin-specific aptamer FETs demonstrated high sensitivities down to 10^-15 M. The functionality of these biosensors was extended to full ionic strength biological fluids, such as an undiluted artificial cerebrospinal fluid. Ultrathin In₂O₃nanoribbon transistor biosensors, fabricated by a straightforward top-down fabrication process, are of great interest for nanoelectronics and next-generation ultrasensitive biosensor platforms.

Saturday November 10 (12:00 – 1:00 PM, 2:50 – 3:35 PM) 2018 Glenn T. Seaborg Symposium, CNSI, UCLA

Nucleic-Acid-Functionalized Field-Effect Transistors for Biomolecule Detection
Kevin M Cheung, Nako Nakatsuka, Kyung-Ae Yang, John M Abendroth, Chuanzhen Zhao, Paul S Weiss, Milan Stojanovic, and Anne M Andrews
1. California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California, United States
2. Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California, United States
3. Division of Experimental Therapeutics, Department of Medicine, Columbia University, New York, New York, United States
4. Biomedical Engineering and Systems Biology, Columbia University, New York, New York, United States
5. Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, and Hatos Center for Neuropharmacology, University of California, Los Angeles, Los Angeles, California, United States

We have designed and developed ultrathin-film field-effect transistors (FETs) coupled to rationally designed and chemically synthesized oligonucleotide sequences with molecular recognition capabilities, termed aptamers, for the specific detection of a diverse range of biologically important small-molecule targets (e.g., neurotransmitters, amino acids, sugars, lipids). Upon target capture, aptamers undergo conformational changes that redistribute charge densities on FET surfaces resulting in measurable changes in conductance. We demonstrate the detection of biomolecules in full ionic strength biological fluids, with high specificity and selectivity, over a wide dynamic range of concentrations with unprecedented detection limits. Using this platform, we are developing sensors for the direct detection of the amino acid phenylalanine for potential point-of-care use for patients with phenylketonuria, a common genetic disorder. Three phenylalanine-specific DNA sequences were investigated to determine sensor responses contingent on different primary base sequences, secondary structures, and target affinities. In parallel, we have extended this FET biosensor platform for the detection and discrimination of single-nucleotide polymorphisms. The development of biosensors with high selectivity and sensitivity in full ionic strength biological fluids presents opportunities for fundamental studies in biological signaling, as well as in precision medicine.

Thursday November 1 (9:00 AM – 10:00 AM) Indian Academy of Sciences, Varanasi, India, November 1 2018

Tuesday October 30 (3:00 PM – 3:45 PM) Indian Institute of Technology, New Delhi, India, October 30 2018

Tuesday October 30 (10:30 AM – 11:15 AM) Jawaharlal Nehru University, New Delhi, India, October 30 2018

Nanotechnology Approaches to Biological Heterogeneity
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Monday October 29 (3:00 PM – 3:45 PM) National Physical Laboratory, New Delhi, India, October 29 2018

Thursday October 25 (9:00 am -10:00 am) (Large Auditorium) Conference on Multifunctional Biomaterials Inspired by Nature, Guimarães, Portugal, Wednesday 24- Friday 26 October 2018

Nanotechnology Approaches to Biological Heterogeneity and Cellular Therapies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Tuesday October 23 (5:40 pm -6:00 pm) Room 102B (Long Beach Convention Center) AVS International Symposium, Long Beach, CA, Sunday 21 – Friday 26, October 2018

Effects of Dimensionality on the Reactivity of Carboxylic-Acid-Terminated Monolayers

Dominic Goronzy, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

Self-assembled monolayers (SAMs) are an advantageous construct to modify surfaces and thereby to tune material properties. Three major determinants affect the spontaneous assembly of monolayers: the substrate-monolayer interface, the interactions between the adsorbate molecules, and the monolayer-environment interface. By controlling the exposed functional groups in the SAM, this interface between the surface and the environment can be probed and manipulated. To examine how exposed carboxyl functional groups modulate the properties of SAMs, we have tethered thiol-functionalized carborane cage molecules with and without a carboxyl group to Au{111} surfaces. Using scanning tunneling microscopy (STM), visualization of the para-functionalized carboxylic acid carboranethiol was only possible in the form of a mixed monolayer of functionalized and unfunctionalized molecules. These experiments demonstrated that the functionalized molecule adopted the same nearest-neighbor spacings on the surface as the unfunctionalized para-carboranethiol, approximately 7.2 Å. By comparison, in our study of carboranethiols with a carboxylic acid functional group attached in the meta position, we have been able to image pure functionalized monolayers via STM with these molecules showing nearest-neighbor spacings of 8.4 Å, approximately 1 Å larger than the unfunctionalized carboranethiols. Studies of two different isomers of meta-carboranethiolate carboxylic acids yielded similar results. In order to examine the effects of changing dimensionality from a 3D solvent system to a 2D thin film, we applied contact angle titration to probe the reactivity of the carboxylic acid head group. These experiments demonstrated a substantial shift from a pKa of 3-3.2 in solution (3D) to an apparent surface pKa of approximately 6.5-7.5. Density functional theory calculations were performed to test the effects of desolvation by 2D confinement and showed shifts in pKa consistent with the experimental data. Together, these results support the concept that the confinement in a 2D environment induces significant changes in reactivity in the molecules, as evidenced by the pKa shift. Thus, precise positioning of functional groups in SAMs is an important tool to investigate the behavior of surface-confined molecules. This system may also serve as a model to explore dimensionality effects in biological systems, including proteins confined within membranes.

Sunday October 21 (1:30 pm -2:05 pm) (Convention & Exhibition Center, Second Floor, AB) Asia Nano, Qingdao, China, Wednesday 24- Friday 26 October 2018

Adding the Chemical Dimension to Lithography at all Scales: Enabling Cellular Therapies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Sunday October 21 (1:30 PM – 2:05 PM) Asia Nano, Qingdao University, College of Materials Science & Engineering and School of Medicine, China, Friday 19 – Sunday 21 October 2018

Adding the Chemical Dimension to Lithography at all Scales: Enabling Cellular Therapies and Studies in Chemical Signaling
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

We control the exposed chemical functionality of substrates from the submolecular to the wafer scale to control biological, chemical, and physical interactions with materials. This work has enabled sensing of signaling molecules. It has also led us to explore the manipulation of the molecules in biological and biomimetic membranes. We introduce biomolecular payloads into cells for gene editing at high throughput for off-the-shelf solutions targeting hemoglobinopathies, immune diseases, and cancers. We circumvent the need for viral transfection and electroporation, both of which have significant disadvantages in safety, throughput, cell viability, and cost. Mechanical deformation can make cell membranes transiently porous and enable gene-editing payloads to enter cells. These methods use specific chemical functionalization and control of surface contact and adhesion in microfluidic channels. Likewise, penetration of reproducibly nanomanufactured, loaded sharp features can introduce these packages into individual or many cells. We discuss our progress with these approaches and the methods that we use to quantify success.

Saturday October 20 (10:30 AM) Titan Student Union Room: Pavillion A (Cal State Fullerton) Far West Section of the American Physical Society, Cal State Fullerton, Fullerton, CA October 18-20 2018

Growth of Gold Nanostars in Flow: A Platform for Antifouling and Small-Molecule Sensing
Gail A. Vinnacombe, Department of Chemistry & Biochemistry and California NanoSystems Institute, UCLA, Los Angeles, CA 90095

Gold (Au) nanostructures are an ideal material for integration into devices for medical and biological applications due to their tunable and unique size-related properties and biocompatibility. In this work, we develop a rapid and scalable strategy for the seed-mediated-growth of branched Au nanoparticles in situ utilizing microfluidics. The synthesized Au nanostars are characterized by strong plasmonic responses in the near infrared, and nanometer tip curvatures that enable efficient photon-to-heat conversion through plasmon-phonon coupling. This localized hyperthermia effect has been employed for the controlled “soft” detachment of adherent cells, which give our platform antifouling properties that can be applied towards the development of microfluidic devices for cell sorting, drug delivery, or transfection. Additionally, we target small-molecule and drug sensing within biological samples via surface-enhanced Raman spectroscopy, due to the Au nanostars’ localized surface plasmon resonance in the biological window. As a test case, we apply this device for the detection of warfarin (an anticoagulant) in the blood at biologically relevant concentrations.

Saturday October 20 (10:30 AM) Titan Student Union Room: Pavillion A (Cal State Fullerton) APS-2018 Annual Meeting of the Far West Section, Fullerton, CA, Thursday 18 – Saturday 20, October 2018

Tuning Surface Work Function through Self-Assembled Monolayers of Carborane Isomers

Dominic Goronzy, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

Self-assembled monolayers (SAMs) are useful platforms to probe the fundamental interactions that drive the spontaneous assembly of nanostructures and to directly modify material properties. In this study, we use carborane-based monolayers to alter the electronic structure of the underlying substrate. The carborane cage molecule is advantageous for this purpose as the strength and direction of the dipole moment of the monolayer molecule can be varied based on which carborane isomer is deposited; through this, we can tune the work function of the surface. Previously, we have been able to modulate the work function of gold and silver surfaces using carboranethiol isomers and of germanium surfaces using carborane‑carboxylic acid isomers. This principle can be further extended by using the O4‑carboranethiol isomer, which has a dipole moment almost perfectly parallel to the surface, or the 9,12‑carboranedithiol isomer, which has a dipole moment almost completely perpendicular to the surface. Furthermore, the effect that the carborane cage dipole has on the surface work function can be used to indirectly track the chemical identity of surface bound molecules, for example in the case of when the SAM is used as a platform for a chemical reaction.

Wednesday 10 October 2018, 4:40 – 5:20 PM

SAHMB Workshop: “International Workshop on Self-Assembly and Hierarchical Materials in Biomedicine: Drug Delivery, Tissue Engineering, Sensing and Safety Issues, San Sebastian, Spain

Gold nanospikes enable capture and release of circulating tumor cells
Leonardo Scarabelli, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

Development of new strategies for diagnosing and monitoring cancer in its early stages are key steps towards more efficient anticancer therapies. Circulating tumor cells (CTCs), malignant cells that break away from primary metastatic lesions, have been proposed as “liquid biopsies”, able to provide real-time information about a patient’s disease status. Improvements in technologies for the screening and collection of CTCs can enable a broad range of clinical applications, including early detection of disease and discovery of new biomarkers to predict treatment responses and disease progression. We are developing and applying a microfluidic platform integrated with nanostructured branched plasmonic interfaces to enable selective capture and recollection of CTCs. Gold nanostars are grown in situ on the interior walls of a glass capillary using a fast and scalable synthetic protocol and are chemically modified with specific antibodies to enable the selective capture of Ewing Sarcoma cells. These nanostructures are characterized by strong plasmonic responses in the near infrared and nanometer tip curvatures that enable efficient photon-to-heat conversion through plasmon-phonon coupling (Figure A and B). This localized hyperthermia effect has been applied for the controlled “soft” detachment of adherent cells, and coupled to our platform and will enable the concentration and collection of captured CTCs for further analysis (Figure C). We aim to develop devices capable of high-throughput detection and isolation of CTCs, enabling early sensing of cells with metastatic potential for monitoring disease.

Monday 8 October 2018, 12:30 – 1:30 PM

Kreidl Memorial Lecture 2018 Rio Grande Symposium on Advanced Materials (RGSAM), Albuquerque, New Mexico

Tuesday 25 September 2018

Nano-Bio Conference 2018, Atlantis Aquila Hotel, Heraklion, Crete, Greece, Monday 24 – Friday 28 September 2018

Nanotechnology Approaches to Biological Cellular Therapies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Wednesday 12 September 2018

NANOSMAT – 2018 Award Lecture, Aud. 1 NE, Gdansk University of Technology, Poland, Tuesday 11 – Friday 14 September 2018

Monday 10 September 2018, 2:50 – 3:15 PM
CSST 2018 Summer Program, NRB Auditorium, UCLA, Los Angeles, CA, Monday 10 September 2018

Precision-Guided Nanoneedles for Targeted and High-Throughput Intracellular Delivery
Xin Gao, Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

An efficient nonviral platform for high-throughput and subcellular precision targeted intracellular delivery of nucleic acids in cell culture based on magnetic nanospears is reported. These magnetic nanospears are made of Au/Ni/Si (∼5 μm in length with tip diameters <50 nm) and fabricated by nanosphere lithography and metal deposition. A magnet is used to direct the mechanical motion of a single nanospear, enabling precise control of position and three-dimensional rotation. These nanospears were further functionalized with enhanced green fluorescent protein (eGFP)-expression plasmids via a layer-by-layer approach before release from the underlying silicon substrate. Plasmid functionalized nanospears are guided magnetically to approach target adherent U87 glioblastoma cells, penetrating the cell membrane to enable intracellular delivery of the plasmid cargo. After 24 h, the target cell expresses green fluorescence indicating successful transfection. This nanospear-mediated transfection is readily scalable for the simultaneous manipulation of multiple cells using a rotating magnet. Cell viability >90% and transfection rates >80% were achieved, which exceed conventional nonviral intracellular methods. This approach is compatible with good manufacturing practices, circumventing barriers to the translation and clinical deployment of emerging cellular therapies.

Thursday 30 August 2018
Biomedical Research Summer Poster Symposium, 158 Hershey Hall, UCLA, Los Angeles, CA

Hydrodynamic cell compression for high-throughput cell transfection
Michael Mellody, Department of Bioengineering, UCLA, Los Angeles, CA 90095

Cell transfection is the process of introducing nucleic acids into eukaryotic cells, resulting in expression of genes not previously found in the cell, or correcting errors in genes to enable the production of corrected transcripts. This process is critical for the development of cellular therapies, which rely on the genetic manipulation of large numbers of cells. To realize this goal, a number of methods have been explored to transfect cells at high throughput. Some microfluidic-based approaches do so via cell deformation, which results in the formation of transient pores in the cell membranes. By forcing cells through channels narrower than the diameter of the cells, the cell membrane is sufficiently disrupted to induce the formation of pores. However, these narrowing channels become clogged over time, significantly reducing throughput. Previous work has described the fabrication of a microfluidic device capable of hydrodynamically deforming cells using the shear forces of two opposing fluid streams. This method of mechanical manipulation is capable of processing thousands of cells per second without cells directly touching the device’s surface, significantly reducing the likelihood of system clogging. This hydrodynamic deformation is repurposed for a high-throughput cell transfection application.

Friday 24 August 2018, 9:00 AM
NanoEngineering for Medicine and Biology Conference, Hershey Room, OMNI Los Angeles Hotel, California Plaza, CA, Tuesday 21 – Friday 24 August 2018

Nanotechnology Approaches to Biological Heterogeneity and Cellular Therapies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Wednesday 22 August 2018, 3:00 PM – 3:20 PM

ACS National Meeting , Room 252B, Boston Convention & Exhibition Center, Boston, Massachusetts, Sunday 19 – Thursday 23 August 2018

Photothermal intracellular delivery using large-area Au nanodisk arrays fabricated by chemical lift-off lithography
Chuanzhen Zhao, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

High-efficiency intracellular delivery is at the heart of the future personalized medicine, with promising applications that include gene editing and modification, intracellular imaging, and drug delivery. Non-viral intracellular strategies have garnered significant attention to achieve high delivery efficiencies and increase cell viabilities, as well as to lower the costs compared with viral-based methods. Photothermal strategies, which use metal plasmonic structures and cavitation bubbles induced by nanosecond laser pulses, have made great strides towards achieving these goals. However, the fabrication process is complicated and hampered by low throughput. Here, we demonstrate the use of large-area arrays of plasmonic gold nanodisks for photothermal intracellular delivery. The Au nanostructures were fabricated using chemical lift-off lithography, which is a large-area, high-throughput, and low-cost patterning strategy developed recently in our group. In this way, nanostructures have been fabricated on a variety of substrates (e.g., petri dishes) that facilitate in situ intracellular delivery in laboratory cell culture environments, demonstrating the ability to integrate this technique with existing medical devices. Nanosecond laser pulses were used to excite the plasmonic nanostructures and locally heat their surroundings, thereby creating transient pores in cell membranes that enable the delivery of biomolecular payloads. Devices were optimized by varying the size and spacing of the Au nanodisks as well as the incident pulse intensity. In doing so, we achieved delivery of 0.6 kDa Calcein into cells with efficiencies of up to 95% and cell viabilities up to 98%.

Wednesday 22 August 2018, 9:45 – 10:10 AM

ACS National Meeting , Room 106, Boston Convention & Exhibition Center, Boston, Massachusetts, Sunday 19 – Thursday 23 August 2018

Aptamer field-effect transistors for small-molecule detection
Kevin M. Cheung, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

We have designed and developed ultrathin-film field-effect transistors (FETs) coupled to rationally designed and chemically synthesized oligonucleotide sequences with molecular recognition capabilities, termed aptamers, for the detection of a diverse range of biologically important small-molecule targets (e.g. neurotransmitters, amino acids, sugars, lipids). Upon target capture, aptamers undergo conformational changes that redistribute charge densities on FET surfaces resulting in measurable changes in conductance. We demonstrate the detection of biomolecules in full ionic strength biological fluids, with high specificity and selectivity, over a dynamic range of concentrations with unprecedented detection limits. Using this platform, we are developing sensors for the direct detection of the amino acid phenylalanine for potential point-of-care use for patients with phenylketonuria, a common genetic disorder. Three phenylalanine-specific DNA sequences were investigated to determine sensor responses contingent on different primary base sequences, secondary structures, and target affinities. In parallel, to elucidate fundamental sensing mechanisms of aptamer-FETs, we worked with aptamers targeting a neutral target, glucose. Glucose aptamer sequence variants (i.e. sequences with different stem lengths) were used to investigate the relationship between distances from FET surfaces and conductance changes. Elucidating aptamer-FET sensing mechanisms is necessary for their ultimate use in biochemical signaling in vivo and for clinical point-of-care applications.

Wednesday 22 August 2018, 9:50 – 10:10 AM

ACS National Meeting , Room 209, Boston Convention & Exhibition Center, Boston, Massachusetts, Sunday 19 – Thursday 23 August 2018

Large-area ultrathin metal-oxide semiconductor nanoribbon arrays fabricated by chemical lift-off lithography
Chuanzhen Zhao, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

We report a high-throughput approach to fabricate arrays of ultrathin In₂O₃ nanoribbon field-effect transistors and biosensors over large areas, enabled by a simple sol-gel process and chemical lift-off lithography (CLL). Transistors channels with larger surface-to-volume ratios exhibit increased sensitivities to adsorbate-induced modifications of their electrical properties. Furthermore, smaller channel widths enable greater areal packing densities and higher spatial resolution when used as sensors. To leverage these trends, we extend CLL to pattern ultrathin films of In₂O₃ (~3 nm) into nanoribbons, 200 nm wide with a pitch of 400 nm. Subsequently, these nanoribbons were used as the semiconducting channels within field-effect transistor arrays, measured to have current on/off ratios over 10⁷ and a peak mobility of ~13.7 cm² V^-1 s^-1. We apply these devices as aptamer biosensors and show them to have high specificity for serotonin with detection limits down to 10^-15 M. Ultrathin In₂O₃ nanoribbon transistors, fabricated by CLL, leverage the advantages of high surface-to-volume ratios and straightforward top-down fabrication techniques and are of great interest for nanoelectronics and ultrasensitive biosensor platforms.

Wednesday 22 August 2018, 9:30 – 9:50 AM

ACS National Meeting , Room 152, Boston Convention & Exhibition Center, Boston, Massachusetts, Sunday 19 – Thursday 23 August 2018

Supported lipid bilayer microfluidics for gene delivery
Jason N Belling, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Gene-editing tools are leading to a new era of personalized medicine and healthcare, and there is strong demand for the development of scalable technologies to edit the genomes of individual cells with high efficiency and speed. Towards this goal, microfluidic systems have emerged as a promising technology that facilitates intracellular delivery of biomolecular cargo based on rapid cell squeezing. As microfluidic technologies transition from conceptual prototypes to functional tools, there is a need to develop next-generation platforms with sustainable processing throughputs where a key objective is to avoid cell clogging. We report a versatile method to passivate microfluidic channels based on noncovalent lipid bicelle technology, leading to dramatic improvements in blocking efficiency against nonspecific protein adsorption and cell adhesion as compared to covalent polymer options. The functional properties of supported lipid bilayers formed viabicelle attachment on both glass and polydimethylsiloxane surfaces were evaluated, including membrane fluidity, passivation against n

onspecific protein adsorption, and inhibition of cell attachment. This surface functionalization approach is now being explored to coat constricted microfluidic devices for the intracellular delivery of biomolecules into cells. This bicelle-based coating strategy enables inhibition of nonspecific protein and cell attachment and is poised to increase the device lifetimes and efficiency of cell transfection.

Tuesday 21 August 2018, 1:10 – 1:45 PM

ACS National Meeting, ACS Patterson-Crane Symposium, Room 156B, Boston Convention & Exhibition Center, Boston, Massachusetts, Sunday 19 – Thursday 23 August 2018

Communicating Opportunities in Nanoscience and Nanotechnology
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Tuesday 21 August 2018, 10:50 – 11:10 AM

ACS National Meeting , Room 157B (Boston Convention & Exhibition Center, Boston, Massachusetts, Sunday 19 – Thursday 23 August 2018

Submolecular resolution spectroscopic imaging for photoactive molecules and assemblies
Shenkai Wang, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

The photoconversion of sunlight directly to electricity is essential for meeting future energy needs. Organic photovoltaic devices consisting of small-molecule donor-acceptor heterojunctions show great promise for photoconversion due to their ease of manufacture, their synthetic variability, and their cost effectiveness. Understanding electron transfer at the molecular level is critical for the rational design and performance optimization of organic optoelectronics and photovoltaics. We use our custom-built laser-assisted scanning tunneling microscope (photon STM) to measure photo-induced charge generation and separation in p-n junctions at the submolecular level under ambient conditions. Photoactive molecules were deposited on sapphire-prism-supported Au{111} substrates to form ordered self-assembled monolayers or were isolated in defects within dodecanethiol self-assembled monolayers. The surfaces were characterized by scanning tunneling microscopy and lasers modulated by a chopper wheel were introduced into the tunneling junction via total internal reflection. The chopper wheel creates a reference frequency input to a lock-in amplifier (LIA) for phase-sensitive detection, so that light-triggered changes in the tunneling current can be recorded and spatially resolved with submolecular resolution. This spectroscopic imaging technique has the potential to elucidate photo-induced carrier dynamics that are inaccessible at ensemble levels and that can be used to direct the rational design and optimization of molecular p-n junctions.

Tuesday 21 August 2018, 10:20 – 10:40 AM

ACS National Meeting, Room 103, Boston Convention & Exhibition Center, Boston, Massachusetts, Sunday 19 – Thursday 23 August 2018

Mechanistic Investigations of Stem-Loop Aptamer Field-Effect Transistors
Nako Nakatsuka, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

Protein-receptor-functionalized field-effect transistor sensors designed for in vivo applications suffer from the inability to circumvent limitations due to screening under physiological conditions due to the large sizes of the protein/antibody-based molecular recognition elements in combination with small (<1 nm) Debye lengths. The Debye length is the distance beyond semiconducting channel surfaces wherein changes in local electric fields affect the distributions of channel free charge carriers to the greatest extent. We overcome this limitation through the use of short, rationally designed oligonucleotide sequences, termed aptamers for molecular recognition. Structure-switching aptamers undergo large conformational changes upon target capture that involve rearrangement of their highly negatively charged backbones in close proximity to semiconducting channels resulting in measurable changes in channel conductances. Coupling aptamers to field-effect transistors, we detected singly charged (serotonin and dopamine), neutral (glucose), and zwitterionic (sphingosine-1-phosphate) small-molecule targets under physiological concentrations. Fluorescence resonance energy transfer studies of glucose and serotonin aptamers indicate that they undergo significant conformational changes, which in the case of glucose also include repositioning of double-helical stems. Further, circular dichroism spectroscopy indicates that some of these aptamers (serotonin and dopamine) have new specific-binding motifs, such as G‑quartets, that are stabilized by target binding. We also systematically altered: (1) the distances at which these repositioning changes in stems occur from the surfaces of channels by increasing aptamer stem lengths, with longer stem lengths leading to decreased signal responses; (2) the densities at which aptamers are positioned on surfaces. These experiments provide new understanding of interactions between aptamers and charge carriers in semiconductors, leading to tunable signals and sensitivities.

Tuesday 21 August 2018, 10:05 – 10:35 AM

ACS National Meeting, Westin Boston Waterfront, Grand Ballroom D Advances in Human Space Exploration: Second ACS NASA Symposium, Boston, Massachusetts, Sunday 19 – Thursday 23 August 2018

Opportunities for and Advantages of Atomically Precise Structures
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Tuesday 21 August, 9:05 – 9:25 AM

ACS National Meeting , Room 103, Boston Convention & Exhibition Center, Boston, Massachusetts, Sunday 19 – Thursday 23 August 2018

Fabrication of aptamer field-effect transistor microprobes towards in vivo neurotransmitter detection
Chuanzhen Zhao, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

Monitoring neurotransmitters in vivo necessitates sensors that approach the spatiotemporal resolution of neuronal communication while differentiating similarly structured neurochemicals with high selectivity. To this end, we have engineered sensors based on chemically synthesized oligonucleotides, termed aptamers, coupled to field-effect transistors. These biosensors show high sensitivity and selectivity for dopamine and serotonin with femtomolar detection limits in vitro. To enable in vivo measurements, we miniaturized our previously reported sensor architecture to fabricate neuroprobes with arrays of aptamer-field-effect transistors. Each implantable microprobe consisted of pairs of interdigitated gold electrodes (transistor source and drain) deposited atop ultrathin, semiconducting indium oxide channels, with an overall width of approximately 120 µm. Functionalization of the exposed semiconducting surface with bio-receptive moieties facilitated electrical sensing via adsorbed aptamer field effects. Increasing the number of interdigitating electrodes (independent transistors) within a single neuroprobe expands its multi-target detection capabilities as well as enables background subtraction via an internal reference. We analyze aptamer surface densities, sensitivity ranges, and detection limits in vitro prior to conducting in vivo measurements and we test for biofouling of neuroprobes using ex vivo measurements in brain tissue homogenates. Implantable aptamer-field-effect transistor-neuroprobes will enable in vivo multiplexed detection of neurotransmitters in the brain with high spatial resolution and selectivity.

Tuesday 21 August 2018, 9:00 – 9:35 AM

ACS National Meeting, Westin Boston Waterfront, Commonwealth Ballroom B, Bioconjugate Chemistry Lectureship & Award: Symposium in honor of Wolfgang Parak, Boston, Massachusetts, Sunday 19 – Thursday 23 August 2018

Monday 20 August 2018, 8 – 10 PM

ACS National Meeting , Exhibit Hall B2/C, Boston Convention Center, Boston, Massachusetts, Sunday 19 – Thursday 23 August 2018

Aptamer-based field-effect transistor nanobiosensor arrays for the simultaneous detection of neurotransmitters
Liv Heidenreich, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

Neuromorphic engineering aims to develop strategies to emulate what is known about neurological architectures and functions in the brain and to use these concepts to improve computing and other processes. However, a purely electronic approach overlooks the chemical nature of neural signaling, where neurotransmitter (chemical) gradients encode information over interpenetrating spatial and temporal domains, and are crucial to the biological functions that underlie emotion, perception, and thought. As a model system to study this process, we are investigating a multi-molecule neuromorphic system that initially utilizes control and detection of two neurotransmitters, serotonin and dopamine, interfaced with microfluidics and a custom circuit board to convert chemical gradients to digital outputs in real-time. We utilize metal oxide semiconductor field-effect transistors (FETs) functionalized with specific recognition units, aptamers, as sensitive analytical components to detect the selective binding of neurotransmitter molecules and to transduce these signals into changes in electrical current. Work is done to characterize figures of merit and to develop quantitative detection. The development of a microfluidics platform enables the simultaneous measurement of multiple analytes in solution and the exploration of the reversibility of the signals. We investigate the time response of neurotransmitter binding to aptamers and calculate k_on, k_off, and K_d values for several aptamer sequences when tethered to FETs. The possible applications of our platform are twofold. As a neuromorphic device, our platforms will be able to receive, to analyze, and to transmit both electrical and chemical signals for information processing. As a sensor, applications extend to sensitive, selective detection of biologically relevant molecules that may be suitable for fast, high-throughput medical screening of patient samples.

Monday 20 August 2018, 8 – 10 PM

ACS National Meeting , Exhibit Hall B2/C, Boston Convention Center, Boston, Massachusetts, Sunday 19 – Thursday 23 August 2018

Supramolecular Assembly onto Polymer-Supported Au Monolayers Fabricated via Chemical Lift-Off Lithography
Gail Vinnacombe, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

We employ chemical lift-off lithography (CLL) – a scalable and economical subtractive patterning technique – to create patterned Au monolayers supported on flexible polymers. In this work, we explore the supramolecular assembly of metal-organic multilayers (MLs) and surface-tethered metal organic frameworks (SurMOFs) on this hybrid material. We characterize the growth using atomic force microscopy, X-ray photoelectron spectroscopy, UV-visible spectroscopy, and contact angle goniometry. Thin films of α,ω-mercaptoalkanoic acids and Cu²⁺ have been used to form hierarchical structures on metal substrates using robust chemical interactions. Studies on multilayer (ML) systems yield important fundamental knowledge regarding molecular self-assembly, while also finding applications in nanoscale electronics and anti-fouling coatings. Similarly, metal-organic frameworks (MOFs) rely on robust metal-organic interactions to form unique porous structures, which enable selective gas up-take. The integration of MOFs into functional electronic devices, photovoltaics, and optical sensors has been realized with the development of surface-tethered MOFs (SurMOFs). We target supramolecular assembly of the HKUST-1 MOF via liquid-phase epitaxy onto underlying hydroxyl (–OH) and carboxy (–COOH) terminations. Through CLL, we take advantage of facile nanoscale pattern fabrication to move towards strategic patterning of metal-organic assemblies on flexible, transparent substrates by controlling surface functionality.

Monday 20 August 2018, 5:00 – 5:20 PM

ACS National Meeting , Room 157A, Boston Convention Center, Boston, Massachusetts, Sunday 19 – Thursday 23 August 2018

Scalable fabrication of one- and two-dimensional gold nanostructures for plasmonic biosensing applications
Chuanzhen Zhao, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

Plasmonic nanostructures made from noble metals have broad application in chemical and biological sensors, food safety, environmental monitoring, and biomedical devices. Scalable techniques to fabricate these structures with dimensions smaller than the wavelengths of visible light are critical to enable their widespread use. In this work, we demonstrate a large-area, high-throughput process to fabricate one-dimensional nanolines and two-dimensional square nanodisks with sub-micron dimensions for use as plasmonic biosensors. Commercially available HD-DVDs were employed as low-cost, large-area “masters” to prepare polymeric stamps with linear features 200 nm wide at a pitch of 400 nm. This pattern was transferred onto gold films via chemical lift-off lithography and selective wet etching, thereby producing large-area arrays of plasmonic Au nanolines. Repeating the patterning process with stamps rotated 90° from the initial patterning orientation enabled the conversion of 1D nanolines to 2D arrays of nanodisks. By tracking peak shifts in the extinction spectra of these plasmonic nanostructures, it was possible to conduct transmission-mode refractometric sensing experiments in aqueous environments, and the corresponding bulk refractive index sensitivities were determined to be in the range of 200–500 nm/refractive index units. These sensing capabilities were translated into high-sensitivity detection of the interactions between these plasmonic nanostructures and different classes of biomacromolecules, namely zwitterionic lipid vesicles and bovine serum albumin protein. Taken together, the results demonstrate how this scalable patterning technique provides a simple and economical means to produce large-area plasmonic nanostructures for a variety of applications in optoelectronics and biosensing.

Monday 20 August 2018, 3:40 – 4:00 PM
ACS National Meeting , Room 157A, Boston Convention Center, Boston, Massachusetts, Sunday 19 – Thursday 23 August 2018

Silicon nanostructures for high-throughput intracellular gene delivery
Chuanzhen Zhao, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

High-throughput intracellular delivery is at the heart of numerous biomedical applications, including the delivery of membrane-impermeable drugs, gene editing, and regenerative medicine. Conventional viral-based strategies suffer from concerns over safety, cell viability, and high costs that have impeded their adoption. Non-viral strategies, such as cell membrane disruption-mediated approaches, have emerged as promising platforms. Direct, physical penetration of cell membranes using sharp nanostructures has been explored as a less destructive method. Here, we fabricate silicon nanovolcanos (SNVs) arrays for delivery of biomolecular cargos with high efficiency while maintaining high cell viability. Using multiple-patterning nanosphere lithography (MP-NSL), SNV structures were prepared with fully tunable geometric parameters (pitch, height, rim diameter, and hole depth), possessing hollow, syringe-like points at the apex, and less than 20 nm wall thickness. The sharp tips of SNVs enable penetration of cell membranes while minimizing disruption of cell functions. Biomolecular payloads loaded into the SNV cavities are delivered inside the cell upon penetration. We demonstrate successful delivery of membrane-impermeable enhanced green fluorescent protein plasmids with 80% transfection efficiency and near 90% cell viability after delivery of nucleic acids. With these advances in high transfection efficiency and viability, SNVs provide a versatile platform for a wide range of fundamental and clinical applications.

Sunday 19 August 2018, 7 – 9 PM

ACS National Meeting , Exhibit Hall B2/C, Boston Convention Center, Boston, Massachusetts, Sunday 19 – Thursday 23 August 2018

Sunday 19 August 2018, 7:00 PM
ACS National Meeting , Exhibit Hall B2/C, Boston Convention Center, Boston, Massachusetts, Sunday 19 – Thursday 23 August 2018

Poster: Single-nucleotide polymorphism detection via ultrathin-film field-effect transistors
Kevin M. Cheung, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

Detecting single-nucleotide polymorphisms (SNPs), which are associated with a variety of diseases, necessitates the development of label-free electronic biosensors for point-of-care applications that can be straightforwardly used in clinical settings. We have designed and fabricated biosensors using ultrathin-film indium oxide field-effect transistors (FETs) that differentiate hybridization of target oligonucleotide sequences with high sensitivity and selectivity. The semiconducting channels of the FETs are chemically functionalized with single-stranded DNA probes to test selectivity towards complementary target sequences versus target sequences that contain SNPs. Hybridization of negatively charged DNA results in significant changes in current responses enabling sensing of DNA hybridization with femtomolar detection limits. By taking advantage of differences in stabilities and conformations of sequences with different base pair mismatches, we demonstrate the ability of DNA-functionalized FETs to distinguish hybridization between fully complementary DNA sequences, and analogous sequences with different types and locations of SNPs. The development and implementation of biosensors that can sense and differentiate oligonucleotide sequences with SNPs at very low concentrations presents new opportunities in the fields of disease diagnostics and precision medicine.

Sunday 19 August 2018, 5:30 – 7:30 PM
ACS National Meeting , Exhibit Hall A, Boston Convention Center, Boston, Massachusetts, Sunday 19 – Thursday 23 August 2018

Sunday 19 August 2018, 12:10 – 12:30 PM
ACS National Meeting , Room 157C, Boston Convention Center, Boston, Massachusetts, Sunday 19 – Thursday 23 August 2018

Saturday 18 August 2018, 11:00 AM

UCLA SPUR Program Talks, 147 Dodd Hall, UCLA, Los Angeles, California

Nanotechnologies for Capturing Circulating Tumor Cells
Angelo Vergnetti, Santa Monica College, Santa Monica, CA 90405

Thursday 16 August 2018, 3:30 – 4:30 PM

UCLA Summer Program, Neuroscience Research Building Lobby, UCLA, Los Angeles, California

Nanotechnologies for Capturing Circulating Tumor Cells
Angelo Vergnetti, Santa Monica College, Santa Monica, CA 90405

Friday 10 August 2018, 11:15 AM – 12:00 PM

2018 UC Mesoscale Materials Summer School, UCI, Irvine, California, Thursday 9 – Friday 10 August 2018

Growing (Up) from the Nanoscale to the Mesoscale
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Wednesday 8 August 2018

Sungkyunkwan University, Seoul, South Korea

Tuesday 7 August 2018

KAIST Advanced Materials Workshop, Daejeon, South Korea, Tuesday 7- Wednesday 8 August 2018

Choosing Scientific Problems and the Resulting Papers
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

We will discuss both personal and editorial experiences of what has led to interesting science and to interesting papers. A specific advantage of nanoscience and nanotechnology has been that we have taught each other approaches from different underlying and parent fields, we have shared our scientific problems, and we have collaborated to look at what new approaches are needed. This coordination has led to new opportunities to move into unexplored areas and to address refractory problems at and beyond the nanoscale.

Monday 6 August 2018

Seoul National University, Department of Physics, Seoul, South Korea

Friday 3 August 2018, 9³⁰ – 10³⁰ AM

A*Star, NanoBio Lab, Biopolis, Singapore

Two seemingly conflicting trends in nanoscience and nanotechnology are our increasing ability to reach the limits of atomically precise structures and our growing understanding of the importance of heterogeneity in the structure and function of molecules and nanoscale assemblies. By having developed the “eyes” to see, to record spectra, and to measure function at the nanoscale, we have been able to fabricate structures with precision as well as to understand the important and intrinsic heterogeneity of function found in these assemblies.I will discuss the challenges, opportunities, and consequences of pursuing strategies to address both precision on the one hand and heterogeneity on the other. In our laboratories, we are taking the first steps to exploit precise assembly to optimize properties such as perfect electronic contacts in materials. We are also developing the means to make tens to hundreds of thousands of independent multimodal nanoscale measurements in order to understand the variations in structure and function that have previously been inaccessible in both synthetic and biological systems.

Thursday 2 August 2018, 9¹⁵ AM

Nanyang Technological University, NTU Library, Singapore

Global Opportunities in Nanoscience and Nanotechnology
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095Two seemingly conflicting trends in nanoscience and nanotechnology are our increasing ability to reach the limits of atomically precise structures and our growing understanding of the importance of heterogeneity in the structure and function of molecules and nanoscale assemblies. By having developed the “eyes” to see, to record spectra, and to measure function at the nanoscale, we have been able to fabricate structures with precision as well as to understand the important and intrinsic heterogeneity of function found in these assemblies.I will discuss the challenges, opportunities, and consequences of pursuing strategies to address both precision on the one hand and heterogeneity on the other. In our laboratories, we are taking the first steps to exploit precise assembly to optimize properties such as perfect electronic contacts in materials. We are also developing the means to make tens to hundreds of thousands of independent multimodal nanoscale measurements in order to understand the variations in structure and function that have previously been inaccessible in both synthetic and biological systems.

Monday 30 July 2018, 9³⁰ AM

Innovations in Materials Science, ShanghaiTech, Shanghai, China, Sunday 29 – Tuesday 31 July 2018

Friday 20 July 2018

Micro- and Nanotechnologies for Medicine: Emerging Frontiers and Applications, UCLA, Los Angeles, CA, Monday 16 – Friday 20 2018

Friday 13 July 2018, 3³⁰ – 4 PM

6th International Conference on Chemical Bonding, Kauai, Hawaii, July 13-17 2018

Cage-Molecule Self-Assembly: Long-Range Interactions and Tests of the Effects of Dimensionality and Confinement in Chemistry
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Self-assembled cage molecules offer an opportunity to test chemical and physical properties because within families of molecules, they form identical lattices. Thus, properties such as atomic arrangements within the cage, molecular and surface dipoles, band alignment, and functional group placement can all be controlled. We describe atomic-scale measurements of coordination and valency, dipole, dipole interactions, hydrogen bonding, band alignment, dimensional effects on pK_a.

Wednesday 27 June 2018

78th Physical Electronics Conference, Durham, New Hampshire, June 26-28 2018

Chiral-Induced Spin Selectivity in Electron Transfer and Transmission through Biomolecular Assemblies
John M. Abendroth and Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry and Biochemistry and Materials Science and Engineering, UCLA, Los Angeles, CA 90095, USA

Recent observations of spin-dependent and enantioselective interactions between electrons and chiral molecules have inspired studies to elucidate the roles of spin and chirality in charge transfer at metal-molecule interfaces. We investigated spin filtering in DNA-mediated charge transfer at room temperature within patterned self-assembled monolayers on ferromagnetic substrates. Using fluorescence microscopy, quenching of photoexcited dye molecules precisely bound within DNA helices was used to analyze substrate magnetization-dependent charge transfer to the surface. Our results suggested that electron spin is preferentially aligned parallel to its propagation direction within this charge-transport regime through right-handed helical DNA duplexes. We also designed experiments using ultraviolet photoelectron spectroscopy to measure the work function of ferromagnetic surfaces functionalized with chiral oligopeptides and proteins. Photoelectrons from ferromagnetic surfaces are spin polarized, while adsorbed chiral molecules act as spin filters. We measured work function differences of tens of millielectron volts that depend on substrate magnetization orientation and the handedness of chiral molecule films. Moving forward, elucidating the mechanistic contributions to spin filtering from adsorbed chiral species, ferromagnetic materials, and metal-molecule interfaces will be critical to assess practicality of chiral organic materials for spintronics applications.

Thursday 13 June 2018

UCLA Biomedical & Life Science Innovation Day, University of California, Los Angeles, June 2018

Aptamer Field-Effect Transistors: Next-Generation in Vivo Neurochemical Biosensors

Kevin M. Cheung, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

Nako Nakatsuka, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

Investigating brain chemistries in real time at the spatiotemporal level of neural circuits and across diverse signaling molecules necessitates neurochemical biosensors that approach these critical attributes. Protein-receptor-functionalized field-effect transistors (FETs) designed for in vivo biosensing suffer from the inability to circumvent limitations due to screening under physiological conditions due to the large sizes of protein receptors in combination with small (<1 nm) Debye lengths. The Debye length is the distance beyond semiconducting channel surfaces wherein changes in local electric fields affect the channel charge distributions to the greatest extent. We overcome this limitation through the use of short, rationally designed oligonucleotide sequences, termed aptamers for molecular recognition. Aptamers can be designed for a range of target detection, response speeds, and in vivo stability. Changes in neurotransmitter concentrations can be monitored via optimized binding-induced aptamer conformational changes that are transduced into electrical signals at the surface of FETs. Serotonin- and dopamine-specific aptamer FETs have high sensitivity with femtomolar detection limits, approximately six orders of magnitude lower than the dissociation constant of the artificial recognition elements. These devices retain their functionality in full ionic strength biological fluids including artificial cerebrospinal fluid and brain tissue with minimal biofouling. In parallel to electronic measurements, we conduct spectroscopy to elucidate the mechanisms by which aptamer-FETs sense neurotransmitters with high specificity and selectivity. We are now miniaturizing aptamer-FETs and fabricating them on neuroprobes to enable investigation of neurochemical signaling directly, in vivo, and in real time.

Monday 11 June 2018

Tel Aviv University, Center for Translational Medicine, Tel Aviv, Israel

Another outcome of the development of our field has been our ability to communicate across fields. This skill that we develop in our students and colleagues has enhanced and accelerated the impact of nanoscience and nanotechnology on other fields, such as neuroscience and the microbiome. I will discuss the opportunities presented by these entanglements and give recent examples of advances enabled by nanoscience and nanotechnology.

Sunday 10 June 2018

Technion, Haifa, Israel

Nanotechnology Approaches to Biological Heterogeneity and Cellular Therapies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Wednesday 6 June 2018

Musher Memorial Lecture, Institute of Chemistry, Hebrew University, Jerusalem, Israel

Monday 4 June 2018, 11:40 AM

C-DOCTOR 2018 Retreat, Ronald Tutor Campus Center (TCC, USC, Los Angeles, California

Novel osteoconductive periodontal membrane
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Wednesday 30 May 2018, 4:20 PM

CDI Pediatrics Symposium, Tamkin Auditorium, Ronald Reagan UCLA Medical Center

Precision-Engineered Nanosystems for the Rapid, Safe, and Efficient Generation of Cellular Therapies
Steven Jonas, California NanoSystems Institute and Department of Pediatrics, UCLA, Los Angeles, CA 90095

Monday 28 May 2018

NSCST, Beijing, China

Nanotechnology Approaches to Biological Heterogeneity and Cellular Therapies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Sunday 27 May 2018

ISBBN, Hunan University, Changsha, China, Friday 25 – Sunday 27 May 2018

We introduce biomolecular payloads into cells for gene editing at high throughput for off-the-shelf solutions targeting hemoglobinopathies, immune diseases, and cancers. We circumvent the need for viral transfection and electroporation, both of which have significant disadvantages in safety, throughput, cell viability, and cost. Mechanical deformation can make cell membranes transiently porous¹ and enable gene-editing payloads to enter cells. These methods use specific chemical functionalization and control of surface contact and adhesion in microfluidic channels. Likewise, penetration of reproducibly nanomanufactured, loaded sharp features can introduce these packages into individual or many cells.² We discuss our progress with these approaches and the methods that we use to quantify success.

Wednesday 16 May 2018, 8 AM

Seattle Convention Center Room 212
Electrochemical Society, Symposium on Solid-state Electronics and Photonics in Biology and Medicine 5, Seattle, WA, Sunday 13 – Thursday 17 May 2018

Sunday 6 May 2018

SJTU Future Information Technology International Forum for Young Scholars (3^rd SIFYS-2018), Session 5: Micro/Nano Electronics and MEMS/NEMS, Shanghai Jiao Tong University, Shanghai, China

Scalable Nanolithography, Nanomotors and Their Biomedical Applications
Xiaobin Xu, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Chemistry and Biochemistry, University of California, Los Angeles, USA

We exploit the phenomena of physics and chemistry at nanoscale, which inspired us toward the development of nanoscience and nanotechnology. Through observation and simulation, we predicted and investigated the nanoscale mechanical deformation and machining of the polymer materials, as well as the mechanical motions of nanoentities under external fields. Strategies were developed for scalable nanomanufacturing to generate large area nanoscale patterns and three-dimensional nanostructures with fully tunability at nanoscale. External fields including electric and magnetic fields were combined with rationally designed and fabricated hybrid nanostructures to develop multifunctional nanomachines with precisely controlled mechanical motions. These multifunctional nanomachines can work as ‘biomedical nanorobots’ to accomplish simple tasks such as assemble into ordered arrays, or move to targeted single cell to do bioanalysis and drug delivery.

Monday 7 May 2018

Zhejiang University of Technology, ZhiZhen Lecture, School of Materials Science and Engineering, Hangzhou, China

Scalable Nanofabrication and Multifunctional Nanomachines Driven by Electric Tweezers
Xiaobin Xu, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

The exploration of physics and chemistry at nanoscale greatly inspires the development of nanoscience and nanotechnology. Through observation and simulation at nanoscale, we predicted and investigated the nanoscale mechanical deformation and machining of the polymer materials, as well as the interaction between the nano-entities and external fields. Based on which, we developed strategies for scalable nanomanufacturing to generate large area nanoscale patterns and three-dimensional nanostructures with fully tunability at sub-20 nm. We also explored electric tweezer techniques, in combination with advanced nanofabrication techniques, we invented multifunctional nanomachines with precisely controlled mechanical motions. These multifunctional nanomachines can work as ‘biomedical nanorobots’ to accomplish simple tasks such as assemble into ordered arrays, or move to targeted single cell to do bioanalysis and drug delivery.

Monday 14 May 2018

TechConnect, Anaheim, CA, Friday 11 – Thursday 17 May 2018

Wednesday 25 April 2018

Nanyang Technological University, Singapore, Wednesday 25 – Thursday 26 April 2018

Nanotechnology Approaches to Biological Heterogeneity and Cellular Therapies
The great promise of single-molecule/assembly measurements is to understand how critical variations in structure, conformation, and environment relate to and control function. New approaches to sensing, imaging, and analysis are keys to elucidating these associations. I will discuss current and upcoming advances and will pose the challenges that lie ahead in creating, developing, and applying new tools for biology and medicine. These advances include using biomolecular recognition in sensor arrays to probe dynamic chemistry in the brain and microbiome systems. It also includes fusing spectroscopic imaging modalities and freeing up bandwidth in measurements to record simultaneous data streams and toexpand our dynamic range. Recent advances in sparsity and compressive sensing can be applied both to new analysis methods and to directing measurements so as to assemble and to converge structural and functional information. Early examples will be discussed.

Tuesday 24 April 2018

IEEE NEMS, Singapore, Sunday 22 – Tuesday 24 April 2018

I will discuss the challenges, opportunities, and consequences of
pursuing strategies to address both precision on the one hand and
heterogeneity on the other. In our laboratories, we are taking the first
steps to exploit precise assembly to optimize properties such as
perfect electronic contacts in materials. We are also developing the
means to make tens to hundreds of thousands of independent multimodal
nanoscale measurements in order to understand the variations in
structure and function that have previously been inaccessible in both
synthetic and biological systems.

Friday 20 April 2018

USC Condensed Matter Physics Seminars, Los Angeles, CA

Global Opportunities in Nanoscience and Nanotechnology
Naihao
Chiang, Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA
90095; School of Materials Science and Engineering, Nanyang
Technological University, Singapore, 637553

During the last few years, there has been an explosion of interest
and activity in the field of nanoscale vibrational spectroscopy. The
goal is to confine and manipulate light on the sub-nanometer length
scale using the properties of the collective electronic excitations in
noble metal nanostructures, known as surface plasmons. An improved
understanding of the interactions between adsorbed molecules and local
environment under various experimental conditions is having a
significant impact in a number of research areas including
electrochemistry, su

ace science, catalysis for energy conversion and storage, low
dimensional materials, biomedical diagnostics, and art conservation
science.

In this presentation, I will focus on three recent advances in
ultrahigh vacuum (UHV) tip-enhanced Raman spectroscopy (TERS) which
illustrate the power of this emerging technique. The first example
demonstrates that TERS reveals more detailed information on the
adsorbate-substrate interacti

which is not easily accessible by other techniques. In the second
example, we interrogated the lifting of an accidental vibrational
degeneracy of self-assembled molecular islands on Ag surfaces due to a
strong lateral intermolecular interaction. This work demonstrates that
UHV-TERS enables direct access of intermolecular interaction at the
nanoscale. Last, I will show our recent results on the adsorption of
molecular oxygen with cobalt phthalocyanine supported on a silver single
crystal surface. This study establishes TERS as a chemically sensitiveS
tool for probing catalytic systems at the molecular-scale.

Monday 16 April 2018

University of Colorado Boulder, Materials and Nanoscience Seminar, Department of Chemistry, Boulder, CO

Saturday 14 April 2018

The 5^th International Forum on Graphene, Shenzhen, China, Wednesday 11 – Saturday 14 April 2018

Friday 6 April 2018

Goldstein Distinguished Lecture, Department of Chemistry & Biochemistry, Cal Poly Pomona, Claremont, CA

Tuesday 26 March 201

University of Science and Technology Beijing, Beijing, China

Nanotechnology Approaches to Biological Cellular Therapies
Paul S. Weiss
California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

November 2017

UCLA Brain Research Institute 29^thAnnual Neuroscience Poster Session, University of California, Los Angeles

Poster: Development of Ultrathin-Film In₂O₃ Field Effect Transistors for Single Nucleotide Polymorphism Detection
Kevin M. Cheung, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

November 2017

Glenn T. Seaborg Symposium, University of California, Los Angeles, Los Angeles, CA

August 2017

Sci-Mix, 254^th ACS National Meeting, Washington, DC

Poster: Detecting Single-Nucleotide Polymorphisms in DNA with Ultrathin Film Field-Effect Transistors
Kevin M. Cheung, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095

August 2017

Division of Colloid and Surface Chemistry, 254^th ACS National Meeting, Washington D.C.

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Online Talks Available

Available online, PuzzleX, Barcelona, Spain, 7 November 2023

Why Grow Meat, Fish, and Tumor Avatars in the Lab?

Available online, Fireside Chat Series, Terasaki Institute, 8 May 2020

Available online, ACS Spring 2020 Meeting

Available online, iCANX, broadcast from Beijing, China, April 2020

Previous Talks

Sunday 14 April 2024, 4 PM, 2033 Young Hall

Alpha Chi Sigma Lecture, UCLA, Los Angeles, CA 90095

From Moving Atoms to Medicine: Exploring the Nanoscale World

Materials Science & Engineering Department Seminar, UCLA, Los Angeles, CA 90095

Control of Chirality, Spin, and Orbitals in Semiconductor-Based Chiral Molecular Devices

Chem 218 Exit Seminar, UCLA, Los Angeles, CA 90095

Atomic-Scale Investigations in Two Dimensions: Self-Assembled Monolayers, Twisted Materials, and MXenes

Tuesday 19 March 2024, 255 PM, Room 229 – Ernest N. Morial Convention Center, New Orleans, LA

American Chemical Society Meeting, Perspectives on Climate Change Literacy & Education: Local to International, New Orleans, LA, 17-21 March 2024

Scalability of Low-Carbon Hydrogen Production to Achieve the Energy Transition

Monday 18 March 2024, 1020 AM, Room 244 – Ernest N. Morial Convention Center, New Orleans, LA

American Chemical Society Meeting, Dreyfus Award in Chemical Imaging Symposium, New Orleans, LA, 17-21 March 2024

Nanoscale Chemical Imaging

Sunday 17 March 2024, 205 PM, Room 223 – Ernest N. Morial Convention Center, New Orleans, LA

American Chemical Society Meeting, New Orleans, LA, 17-21 March 2024

Measuring and Leveraging Local Structure in Materials for Hydrogen Storage

Friday 8 March 2024, 235 PM

Beauty Accelerate Conference, The Millenium Biltmore Hotel, Los Angeles, CA

Inclusive Beauty: Product Design for Deeper Skin Tones

Friday 8 March 2024, 1 PM

Geffen Academy, Los Angeles, CA

Nanotechnology Approaches to Biotechnology, Medicine, and Sustainability

Thursday 7 March 2024, 4 PM, Conference Center, Room M100H

American Physical Society Meeting, Minneapolis, MN, 4-8 March 2024

Square-Root Topological Graphene Nanoribbons Modulated by Electric Field

Tuesday 5 March 2024, 12:06 PM, Conference Center, Room 101B

American Physical Society Meeting, Minneapolis, MN, 4-8 March 2024

Chirality-Induced Magnet-Free Spin Generation in Semiconductors

Tuesday 5 March 2024, 11:30 AM, Conference Center, Room 101B

American Physical Society Meeting, Minneapolis, MN, 4-8 March 2024

Control of Chirality, Spin, and Orbitals in Semiconductor-Based Chiral Molecular Devices

Thursday 8 February 2024, 3:50 PM (local time)

Advancement in Chemical and Biological Research: Breaking Boundaries and Shaping the Future, Tarsadia Institute of Chemical Science, Bardoli, Gujarat, India

Nanotechnology Approaches to Biotechnology, Medicine, and Sustainability

Wednesday 24 January 2024, 2 PM

2024 International Conference on Superwettability+, LEO 1-4 Resorts World Convention Centre, Level 1, Sentosa, Singapore, 24 – 25 January 2024, Plenary Lecture

Understanding and Controlling Interactions and Properties at Atomically Precise Interfaces

Wednesday 24 January 2024, 11:30 AM

National University of Singapore Innovation Symposium, Singapore, LT 37, MD 1 Tahir Building

Taking on Unsolved Problems in Healthcare Disparities through Nano- and Biotechnologies

Friday 19 January 2024

UCLA Department of Chemistry & Biochemistry Seaborg Award Symposium Poster Session, CNSI, UCLA, Los Angeles, CA

Atomic-Scale Exploration of Functional Ti3C2 MXenes

Sunday 18 December 2023

IIT Madras, Chennai, Tamil Nadu, India

Translating Nanotechnology Advances in Biotechnology, Medicine, and Sustainability

Friday 16 December 2023

International Conference on Molecular Matter, Chennai, Tamil Nadu, India, 16-18 December 2023

Advancing Sustainability through Control of Charge, Heat, and Spin at Atomically Precise Interfaces

Friday 1 December 2023

Institute for Neuro Innovation Research Symposium and Gala, Santa Monica, CA

Taking on Unsolved Problems and Healthcare Disparities

Tuesday 28 November 2023

University of New South Wales, Australian Centre for NanoMedicine, Sydney, NSW, Australia

Translating Nanotechnology Advances in Biotechnology, Medicine, and Sustainability

Saturday 18 November 2023

Samsung Science & Technology Foundation Global Research Symposium: Molecules and Materials in Nanoscience and Beyond, Beverly Hills, CA, November 15-18, 2023

Understanding and Controlling Charge, Heat, and Spin at Atomically Precise Interfaces

Sunday 12 November 2023

Institute of Molecular Medicine, Hangzhou, China

Translating Nanotechnology Advances in Biotechnology, Medicine, and Sustainability

Tuesday 7 November 2023

PuzzleX, Barcelona, Spain

Mysteries of the Brain

Tuesday 7 November 2023

PuzzleX, Barcelona, Spain

Why Grow Meat, Fish, and Tumor Avatars in the Lab?

Friday 27 October 2023

Northwestern University, Center for Molecular Quantum Transduction, Evanston, IL

Understanding and Controlling Charge, Heat, and Spin at Atomically Precise Interfaces

Friday 20 October 2023

Republic of the Philippines, Department of Science and Technology, Philippine Council for Industry, Energy, and Emerging Technology Research and Development (PCIEERD), Manila, The Phillipines (by Zoom)

A Career in Nanoscience So Far: From Fundamental Science to Translational and Commercialization

Tuesday 19 March 2024, 2⁵⁵ PM, Room 229 – Ernest N. Morial Convention Center, New Orleans, LA

Monday 18 March 2024, 10²⁰ AM, Room 244 – Ernest N. Morial Convention Center, New Orleans, LA

Sunday 17 March 2024, 2⁰⁵ PM, Room 223 – Ernest N. Morial Convention Center, New Orleans, LA

Friday 8 March 2024, 2³⁵ PM

Atomic-Scale Exploration of Functional Ti₃C₂ MXenes

**Design of ex Vivo Tissue Studies to Elucidate Melanosome and Epidermal Function in Darker Skin Tones**

Understanding and Controlling Charge, Heat, and Spin at
Atomically Precise Interfaces

Understanding and Controlling Charge, Heat, and Spin at
Atomically Precise Interfaces