You missed us!
Here are some abstracts of talks that we have given.

A Career in Nanoscience (So Far)
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

I will discuss career choices and how to choose and to target scientific goals. I will discuss how we select specific problems and the thinking and arguing that goes into putting together the people, resources, and experiments to address them. My own route to nanoscience has been circuitous. My group is intentionally diverse in terms of background, with members from chemistry, engineering, materials science, mathematics, neuroscience, and physics. We teach each other languages and approaches. We bring together different perspectives to identify the key parts of the scientific problems we address.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

Atomic-scale measurements of graphene nanoribbon edge
Patrick Han (Tohoku Univ), Katsuya Iwaya (RIKEN), Susumu Shiraki (Tohoku Univ), Naoki Asao (Tohoku Univ), Taro Hitosugi (Tohoku Univ), Paul Weiss (UCLA)

Graphene edges are predicted to be a type of defects that can be utilized to tailor both the electronic and the magnetic properties of graphene structures. However, to date, there is little experimental result on how graphene size and structure affect these edge properties. For this purpose, we fabricate defect-free graphene nanoribbons (GNRs) by self-assembly of organic precursor molecules on a Cu(111) single-crystal surface in ultrahigh vacuum. We use low-temperature scanning tunneling microscopy to image and measure the electronic properties of these ribbons, comparing GNR edges and centers. We discuss the results of our fabrication process and of our local spectroscopic measurements of individual GNRs.

Developing Nanoscale Measurements for the Brain
Paul S. Weiss and Anne M. Andrews, California NanoSystems Institute, UCLA, Los Angeles, CA 90095

Since important functions of the brain occur at the nanoscale, it is anticipated that nanoscale tools can be developed to study and to interact with the brain and its component parts (see Alivisatos et al., ACS Nano 7, 1850, 2013). We and others have moved to develop these tools and methods. In our initial work, we functionalized surfaces with isolated and tethered neurotransmitters. These capture surfaces are being used to pull down the membrane-associated proteins from the brain involved in neurotransmission as well as to select molecules to use as artificial receptors for in vivo measurements. The latter will be used to study chemical neurotransmission dynamically at high spatial resolution in many simultaneous parallel measurements. Parallel measurements of voltage activity are further along, such that several thousand measurements can now be made simultaneouly with a single multiplexed probe. Ultimately, the great heterogeneity of the brain will require many parallel and specific chemical and voltage measurements, so as to understand and to stimulate neural circuits. This understanding is the goal of the recently announced Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative in the United States. With an initial focus on technology development, there are great opportunities not only to study the brain, but also to understand to learn to treat diseases of the brain. Understanding how neural circuits function and how they malfunction will be critical to these efforts.

Developing Nanoscale Measurements for the Brain
Paul S. Weiss and Anne M. Andrews, California NanoSystems Institute, UCLA, Los Angeles, CA 90095

Since important functions of the brain occur at the nanoscale, it is anticipated that nanoscale tools can be developed to study and to interact with the brain and its component parts (see Alivisatos et al., ACS Nano 7, 1850, 2013). We and others have moved to develop these tools and methods. In our initial work, we functionalized surfaces with isolated and tethered neurotransmitters. These capture surfaces are being used to pull down the membrane-associated proteins from the brain involved in neurotransmission as well as to select molecules to use as artificial receptors for in vivo measurements. The latter will be used to study chemical neurotransmission dynamically at high spatial resolution in many simultaneous parallel measurements. Parallel measurements of voltage activity are further along, such that several thousand measurements can now be made simultaneouly with a single multiplexed probe. Ultimately, the great heterogeneity of the brain will require many parallel and specific chemical and voltage measurements, so as to understand and to stimulate neural circuits. This understanding is the goal of the recently announced Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative in the United States. With an initial focus on technology development, there are great opportunities not only to study the brain, but also to understand to learn to treat diseases of the brain. Understanding how neural circuits function and how they malfunction will be critical to these efforts.

New Dimensions in Patterning: Placement and Metrology of Chemical Functionality at All Scales
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We place single molecules and larger groups into precisely controlled environments on surfaces. Monolayer matrices and inserted molecules and sub-assemblies can be designed so as to interact directly, to give stability or other properties to supramolecular assemblies. New families of molecules are being developed to yield even greater control and are enabling determination of the key design parameters of both the molecules and assemblies. This, in turn, is enabling hierarchically controlled chemical patterning and selective functionalization from the sub-nanometer to the centimeter scales. We are simultaneously developing a suite of metrology tools for these methods to give unprecedented information on the structures and properties of these assemblies.

Developing scanning probe techniques for the analysis of biomolecules
Miles Silverman, Paul S. Weiss, Andrea Bertozzi, Stan Osher, Joseph Woodward, Konstantin Dragomiretzskiy, Travis Meyer, John Thomas, and Shelley Claridge, California NanoSystems Institute, UCLA, Los Angeles, CA 90095, USA

Developing scanning probe techniques for the analysis of biomolecules
Miles Silverman, Paul S. Weiss, Andrea Bertozzi, Satn Osher, Joseph Woodward, Konstantin Dragomiretzskiy, Travis Meyer, John Thomas, and Shelley Claridge, California NanoSystems Institute, UCLA, Los Angeles, CA 90095, USA

Selective deposition, reactions, and interactions of molecules and assemblies in controlled chemical environments
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We control access of molecules from solution, vapor, and/or contact to substrates in order to place molecules and assemblies selectively in controlled chemical environments. Reactions of isolated molecules can proceed without disrupting surface-bound nanostructures. The reaction exothermicity of clustered molecules can disrupt the structures and can be used to enable access to the substrate and further deposition. The functionalized surfaces can be used to control chemical, biological, and physical interactions. The lability of these surfaces can be turned back off so as to preserve and to stabilize the nanostructures and chemical patterns formed.

Electronic Structure, Assembly, and Chemistry of Precise Clusters
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Precise clusters offer a new set of building blocks with unique properties that can be leveraged both individually and in materials in which their coupling can be controlled by choice of linker, dimensionality, and structure. Initial measurements in both of these worlds have been made. Isolated adsorbed or tethered clusters are probed with low-temperature scanning tunneling microscopy and spectroscopy. Even closely related elements behave differently on identical substrates. Surprising spectral variations are found for repeated measurements of single isolated, tethered clusters. In periodic solids, precise clusters joined by linkers can be measured experimentally and treated theoretically with excellent agreement, in part due to the relatively weak coupling of the clusters. This coupling can be controlled and exploited to produce materials with tailored properties. Some of the rules for predicting these properties are being developed through these initial studies and the limit to which they can be applied is being explored.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

Precise Assembly and Directed Multimodal Measurements for Understanding Nanoscale Systems
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Subnanometer Spatial Resolution Chemical Imaging
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

The Ultimate Limits of Miniaturization: Exploring and Controlling the Nanoscale World in Science, Engineering, and Medicine
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Since we have learned to measure the precise structures, environments, interactions, and functions of molecules at the nanoscale, we are now learning to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measurements of single or coupled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited. We examine how these interactions influence chemistry, dynamics, structure, electronic function, and other properties. Such interactions can be used to advantage to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. By understanding interactions, function, and dynamics at the smallest possible scales, we hope to improve improve synthetic systems at all scales. We are also using these strategies to control and to understand interactions, function, and structures of biological systems. I will discuss upcoming opportunities to make inroads into refractory problems in biology and medicine, and will discuss our first results and approaches in these areas.

The Ultimate Limits of Miniaturization: Exploring and Controlling the Nanoscale World in Science, Engineering, and Medicine
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Since we have learned to measure the precise structures, environments, interactions, and functions of molecules at the nanoscale, we are now learning to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measurements of single or coupled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited. We examine how these interactions influence chemistry, dynamics, structure, electronic function, and other properties. Such interactions can be used to advantage to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. By understanding interactions, function, and dynamics at the smallest possible scales, we hope to improve improve synthetic systems at all scales. We are also using these strategies to control and to understand interactions, function, and structures of biological systems. I will discuss upcoming opportunities to make inroads into refractory problems in biology and medicine, and will discuss our first results and approaches in these areas.

The Ultimate Limits of Miniaturization: Exploring and Controlling the Nanoscale World in Science, Engineering, and Medicine
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Since we have learned to measure the precise structures, environments, interactions, and functions of molecules at the nanoscale, we are now learning to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measurements of single or coupled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited. We examine how these interactions influence chemistry, dynamics, structure, electronic function, and other properties. Such interactions can be used to advantage to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. By understanding interactions, function, and dynamics at the smallest possible scales, we hope to improve improve synthetic systems at all scales. We are also using these strategies to control and to understand interactions, function, and structures of biological systems. I will discuss upcoming opportunities to make inroads into refractory problems in biology and medicine, and will discuss our first results and approaches in these areas.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

Function and Reaction in Precise Assemblies on Flat and Curved Surfaces
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

Mapping Locally Aligned Dipoles within Two-Dimensional Plastic Lattices and Majority Thiol vs Thiolate Control in Carboranedithiolate Monolayers
John C. Thomas,^1,2 Jeffrey J. Schwartz,^1,3 Harsharn Auluck,^1,2 Brandon Matthews,^1,2 Jackie Dermenjian,^1,2,4 Giang Tran,^1,5 Andrea Bertozzi,^1,5 Jerome Gilles,^1,5 Stan Osher,^1,5 Chad A. Mirkin,⁶ Tomas Basé,⁷ and Paul S. Weiss,^1,2,8
1California NanoSystems Institute, UCLA, Los Angeles, CA 90095, USA
²Department of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095, USA
³Department of Physics, UCLA, Los Angeles, CA 90095, USA
⁴Marlborough School, Los Angeles, CA, USA
⁵Department of Mathematics, UCLA, Los Angeles, CA 90095, USA
⁶Department of Chemistry, Northwestern University, Evanston, IL, USA
⁷Institute of Inorganic Chemistry, Czech Academy of Science, Prague, Czech Republic
⁸Department of Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Quasi-two-dimensional dipole alignment is mapped within self-assembled monolayers (SAMs) of carboranethiolate molecules with an ultrastable, custom-built scanning tunneling microscope (STM) held at 4 K. Scanning tunneling micrographs in topographic and local barrier height modes depict the respective positions of molecules' geometric apexes and largest locally buried dipole moments with sub-Ångström precision. Juxtaposing these simultaneously acquired images, we observe unidirectional offsets between the molecular apex and dipole maxima within domains. We determine dipole orientations using new image analysis techniques and observe alignment across SAM molecular domain boundaries. The alignment observed, consistent with Monte Carlo simulations, forms through favorable intermolecular dipole-dipole interactions at low temperatures (4.2 K). We measure and compare two different isomeric (o-9-carboranethiolate and m-1-carboranethiolate) monolayers. We also present a new molecule, 1,2-carboranedithiol, where measurements and theory suggest two binding configurations. Exposing these bifunctional molecules to acid and base switches molecules between majority monovalent and divalent binding, respectively.

New dimensions in patterning: Placement and metrology of chemical functionality at all scales
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We place single molecules, as well as pairs, lines, clusters, and larger groups of molecules into precisely controlled environments on surfaces. Monolayer matrices and inserted molecules and sub-assemblies can be designed so as to interact directly, to give stability or other properties to supramolecular assemblies. The exposed interface can be engineered to control physical, chemical, electronic, and biological properties. New families of molecules, particularly upright, symmetric cage molecules, are being developed to yield even greater control and are enabling determination of the key design parameters of both the molecules and assemblies. This, in turn, is enabling hierarchically controlled chemical patterning and selective functionalization from the subnanometer to the centimeter scales. We are simultaneously developing a suite of metrology tools for these methods to give unprecedented information on the structures and properties of these assemblies.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

Chemical Lift-Off Lithography for the Fabrication of Ultrasensitive Neurotransmitter Biosensors
Hannah L. Hinton, Jaemyung Kim, Paul S. Weiss, and Anne M. Andrews, California NanoSystems Institute and Departments of Chemistry & Biochemistry, Materials Science & Engineering, and Psychiatry, UCLA, Los Angeles, CA 90095, USA

While neurochemical measurements have been critical in advancing our understanding of chemical reactions in the central nervous systems, biosensors capable of measuring neurochemicals are limited by the resolution of the techniques used to fabricate them. Chemical lift-off lithography (CLL) is a technique that can produce high-resolution patterns on a large scale without the need for special equipment. The aim of this project is to utilize CLL to develop highly sensitive biosensors that can detect trace amounts of neurotransmitters such as dopamine. Facile patterning of field-effect transistor electrodes on a large scale was achieved using CLL, and the same technique was used to fabricate a bio-sensing device using In₂O₃ nanobelts as the semiconducting device material. Biosensors with less than 100-nm feature size were fabricated, and it is anticipated that they will have ultrahigh sensitivity in the detection of dopamine and neurotransmitters. To test the biosensors, biologically active entities such as aptamers will be covalently attached to the sensing platform of the device, and the device will be exposed to various neurotransmitters to determine the sensitivity and the selectivity of the biosensor. The generation of a biosensor capable of measuring trace levels of neurotransmitters will set the framework for future studies exploring previously undetectable dynamic chemistry in the brain.

Cage Molecule Self-Assembly
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We have shown that upright, symmetric cage molecules self-assembled on surfaces have simple domain and defect structures.^1-4 Unlike linear molecules, such as alkanethiols on Au{111}, these cage molecules do not tilt and do not conformationally relax. The lattices of the cage molecules appear to be determined by the projections of the cages on the surface. Thus, different isomers, such as carboranethiols on Au{111}, form identical lattice structures. These monolayers enable key tests of simple phenomena, such as the effects of dipole moment direction and amplitude.² For example, molecules with dipoles parallel to the surface form nonpolar monolayers and outcompete molecules with dipoles normal the surface, which form polar monolayers. These properties can be measured both at the macroscopic and nanoscopic scales. We interpret the enhanced stability of the nonpolar surfaces to aligned dipoles in the monolayers and set out to measure such effects.⁵ Using combinations of spectroscopic imaging and novel image analyses, we find that dipoles do align, even across domain boundaries.

We have also measured multifunctionalized cage molecules and shown that we can protonate and deprotonate thiol(ate)s to change the valency of attachment to the surface through simple reactions.

The future of boron-containing cage molecules for self-assembly will be discussed further in terms of tailoring intermolecular interactions and in building off surfaces in three dimensions.

¹A. A. Dameron, L. F. Charles and P. S. Weiss, J. Am. Chem. Soc., 2005, 127, 8697.
²J. N. Hohman, P. P. Zhang, E. I. Morin, P. Han, M. H. Kim, A. R. Kurland, P. D. McClanahan, V. P. Balema and P. S. Weiss, ACS Nano, 2009, 3, 527.
³J. N. Hohman, S. A. Claridge, M. H. Kim and P. S. Weiss, Matl. Sci. Eng. Rep., 2010, 70, 188.
⁴S. A. Claridge, W.-S. Liao, J. C. Thomas, Y. Zhao, H. Cao, S. Cheunkar, A. C. Serino, A. M. Andrews and P. S. Weiss, Chem. Soc. Rev., 2013, 42, 2725.
⁵P. Han, A. R. Kurland, A. N. Giordano, S. U. Nanayakkara, M. M. Blake, C. M. Pochas and P. S. Weiss, ACS Nano, 2009, 3, 3115.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperatively.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Exploring the Ultimate Limits of Miniaturization
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single molecules and assemblies. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements of structure, function, and spectra in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

Developing Nanoscale Measurements for the Brain
Anne M. Andrews, Departments of Psychiatry and Chemistry & Biochemistry and California NanoSystems Institute and Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Since important functions of the brain, such as intercellular chemical and information transfer, occur at the nanoscale, we are developing nanoscale tools to study and to interact with the brain and its component parts (see Alivisatos et al., ACS Nano 7, 1850, 2013). We have brought the great investment and advances in nanoscience and nanotechnology over the last decade to accelerate our understanding of the brain, in both health and disease. In our initial work, we functionalized surfaces with isolated and tethered neurotransmitters, the small molecules used in this chemical communcation. These capture surfaces are being used to pull down the proteins from the brain involved in neurotransmission as well as to select molecules to use as artificial receptors for in vivo measurements. The latter will be used to study chemical neurotransmission dynamically at high spatial resolution in many simultaneous parallel measurements. Parallel measurements of voltage activity are further along, such that several thousand measurements can now be made simultaneouly with a single multiplexed probe. Ultimately, the great heterogeneity of the brain will require many parallel and specific chemical and voltage measurements, so as to understand and to stimulate neural circuits. This understanding is the goal of Pres. Obama's Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative in the United States and complementary efforts around the world. With an initial focus on technology development, there are great opportunities not only to study the brain, but also to learn to treat diseases of the brain. Understanding how neural circuits function and how they malfunction will be critical to these efforts.

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

A Career in Nanoscience So Far
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

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

In three decades of nanoscience and nanotechnology, we have explored the ultimate limits of miniaturization - placing and measuring single atoms and molecules. While we have advanced the field by combining synthesis, measurement, theory, and simulation, we have not yet developed the intuition to understand the dominant forces in this nanoscale world. Now, we are moving to the next higher level of hierarchy, and to more complex assemblies. Enhanced and new tools and methods will need to be developed to determine structure and function at the mesoscale, so as to guide both understanding and applications. I will discuss the challenges and opportunities ahead and some promising approaches to address mesoscale structures and properties.

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

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

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

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

The Ultimate Limits of Miniaturization: Exploring and Controlling the Nanoscale World in Science, Engineering, and Medicine
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Nanoscale Optical Interactions in Precise Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

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 (Claridge et al., 2013; Zheng et al., 2013). We have developed and applied new tools based on the scanning tunneling microscope (STM) to measure structure, function, and spectra simultaneously (Moore et al. 2010; Claridge et al., 2011; Pathem et al., 2013). We are particularly interested in the interactions of photons with precisely assembled structures. Much previous work in this area has been limited by the absorption of light by the STM tip, resulting in heating and making quantitative measurements difficult. We have overcome this difficulty by coupling light evanescently into the tunneling junction using specially prepared substrates and a new set of STMs. The measured results of photoexcitation include photoconductivity and regioselective reaction (Kim et al., 2011; Zheng et al., 2012). We are applying this method to optimize molecules and materials for energy conversion and storage (Chen et al., 2012). Related imaging spectroscopies we have developed give access to the cooperative action of assembled molecular motors and the identification and orientations of parts of molecules such as amyloid-forming oligopeptides. Complementary far-field measurements enable statistically significant optical measurements of function, dynamics, and chemical environment. We are applying the assembly strategies that we have developed for flat surfaces to curved and faceted substrates while measuring the environment, interactions, and dynamics of molecular probes designed for this purpose (Zheng et al., 2012).

Acknowledgments: We acknowledge support from the US Department of Energy for this work.

References
Chen CC, Dou L, Zhu R, Song T-B, Zheng YB, Chung CH, Li G, Weiss PS, Yang Y, 2012. Visibly transparent polymer solar cells produced by solution processing. ACS Nano 6: 7185-7190.

Claridge SA, Schwartz JJ, Weiss PS, 2011. Electrons, photons, and force: Quantitative single-molecule measurements from physics to biology, ACS Nano 5: 693-729.

Claridge SA, Liao W-S, Thomas JC, Zhao Y, Cao ., Cheunkar S, Serino AC, Andrews AM, Weiss PS, 2013. From the bottom up: Dimensional control and characterization in molecular monolayers. Chemical Society Reviews 42: 2725-2745.

Kim MH, Hohman JN, Cao Y, Houk KN, Ma H, Jen AK-Y, Weiss PS, 2011. Creating favorable geometries for directing organic photoreactions in alkanethiolate monolayers. Science 331: 1312-1315.

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.

Pathem BK, Claridge SA, Zheng YB, Weiss PS, 2013. Molecular switches and motors on surfaces. Annual Review of Physical Chemistry 64: 605-630.

Zheng YB, Payton JL, Song T-B, Pathem BK, Zhao Y, Ma H, Yang Y, Jensen L, Jen AK-Y, Weiss PS, 2012. Surface-enhanced Raman spectroscopy to probe photoreaction pathways and kinetics of isolated reactants on surfaces: Flat vs. curved substrates. Nano Letters 12: 5362-5368.

Zheng YB, Pathem BK, Hohman JN, Thomas JC, Kim MH, Weiss PS, 2013. Photoresponsive molecules in well-defined nanoscale environments. Advanced Materials 25: 302-312.

Conserved Chemical Lift-Off of Optically Transparent Gold Patterns onto Polymer Supports
Liane Siu Slaughter,^1,2 Qing Yang,^1,2 Thomas D. Young,^1,2 Huan Cao,^1,2 Andrew Serino,^1,2,3 Anne M. Andrews,^1,2,4 and Paul S. Weiss^1,2,3
1California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California, USA, Email: slaughter@chem.ucla.edu
²Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California, USA
³Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, California, USA
⁴Department of Psychiatry and Biobehavioral Health and Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, California 90095, USA

Gold nanostructures with dimensions <5 nm have optical and chemical activity distinct from larger nanostructures.^1-3 By placing them in well-defined positions, their functionalities become spatially encoded, a feature that will enable multiplexed investigative technologies. We show that chemical lift-off lithography (CLL), a recently developed subtractive patterning method (Figure 1),⁴ can cheaply, efficiently, and reusably print ultrathin films of organometallic gold species in user-defined patterns onto otherwise topographically featureless polydimethylsiloxane (PDMS), a transparent, inexpensive, and biocompatible polymer. Through chemical bonding between the hydroxyl-terminal groups of the self-assembled monolayer (SAM) molecules and oxygen-activated PDMS, this subtractive stamping technique enables parallel printing of the gold species into lines, circles, squares, and holes with lateral dimensions spanning hundreds of nanometers to microns. The gold masters can be reused for multiple cycles of SAM formation and chemical lift-off to pattern many PDMS substrates, thereby minimizing the amount of gold consumed when patterning multiple PDMS substrates. By demonstrating the same result by starting with a pattern of hydroxyl- and methyl-terminated SAM molecules instead of patterned gold, we test the chemical selectivity of the lift-off mechanism that enables transfer of a limited number of atoms from the gold surface onto the PDMS.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

Nanoscience Approaches to Heterogeneity in Biological Systems
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 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 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.

Exploring the Ultimate Limits of Miniaturization in Science, Engineering, and Medicine
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.¹ New approaches to 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 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.

¹Electrons, Photons, and Force: Quantitative Single-Molecule Measurements from Physics to Biology, S. A. Claridge, J. J. Schwartz, and P. S. Weiss, ACS Nano 5, 693 (2011).

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

Surface Photo-Activation of Single Molecules and Assemblies on Au{111}
Yuxi Zhao, Moonhee Kim, Natcha Wattanatorn, Jeffrey Schwartz, Hong Ma, Alex Jen, and Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, NMaterials Science and Engineering, and Physics, UCLA, Los Angeles, CA 90095, USA and Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA

Understanding electron transfer at the molecular level is critical to the rational design and performance improvement of organic optoelectronics and photovoltaics. The behavior of photoactive molecules depends critically on their local environment and defects present in the surface. Here, we use a custom-built, laser-assisted scanning tunneling microscope to probe the photocurrent of isolated anthracene derivates on Au\textbraceleft 111\textbraceright . The photocurrent originates from charge-transfer transitions of anthracene into an excited state when illuminated by an evanescent field. The influence of the image potential states on terraces and at defects in the gold surface on photo-induced charge transfer will be discussed.

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

Surface Dipole Control of Liquid Crystal Alignment
Jeffrey Schwartz, Yuxi Zhao, Alexandra Mendoza, Natcha Wattanatorn, and Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry, NMaterials Science and Engineering, and Physics, UCLA, Los Angeles, CA 90095, USA

We investigate the influence of surface dipoles on the alignment of liquid crystals (LCs). Carboranethiol self-assembled monolayers (SAMs) are shown to induce planar anchoring in 4-cyano-4'-pentylbiphenyl LCs at the SAM/nematic interface. We exploit the different dipole moments of carboranethiol structural isomers in order to deconvolve the influence of SAM-LC dipolar coupling from variations in molecular geometry, tilt, and order. The LC director orientation and anchoring energy are measured for devices employing varying caboranethiol isomer alignment layers. By using LC orientation as a probe of interaction strength, we demonstrate that dipolar coupling of SAMs to their environment plays a key role in determining molecular orientations. This understanding may advance the engineering of molecular interactions at the nanoscale.

Probing Buried and Exposed Interfaces with Submolecular Precision
John C. Thomas, California NanoSystems Institute and Department of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095, USA

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

The great promise of single-molecule/assembly measurements is to understand how critical variations in structure, conformation, and environment relate to and control function.¹ New approaches to 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 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.

¹Electrons, Photons, and Force: Quantitative Single-Molecule Measurements from Physics to Biology, S. A. Claridge, J. J. Schwartz, and P. S. Weiss, ACS Nano 5, 693 (2011).

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

The great promise of single-molecule/assembly measurements is to understand how critical variations in structure, conformation, and environment relate to and control function.¹ New approaches to 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 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.

¹Electrons, Photons, and Force: Quantitative Single-Molecule Measurements from Physics to Biology, S. A. Claridge, J. J. Schwartz, and P. S. Weiss, ACS Nano 5, 693 (2011).

Ethics in publishing: Editorial and related experiences
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

At ACS Nano, as editors, we have encountered a variety of ethical issues. These came not only from inexperienced authors, but from all corners. Sitting at the crossroads of many fields gives us an interesting perspective on the approaches taken across fields and borders. A selection of these will be discussed.

Award Address: Assembly and measurements of isolated and coupled functional molecules
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Surface Interaction Potentials and Dynamics: Quantitative Measurements and Implications
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Our first atomic-resolution measurements of isolated and dilute interacting atoms and molecules on surfaces with scanning tunneling microscopy and spectroscopy revealed long-range, anisotropic, energy-dependent perturbations on electronic structure. Spectroscopic imaging enables energy- and spatially resolved measurements of electronic structure, but we have not yet been able to invert these perturbations directly into adsorbate potentials. Thus far, we have used measurements of adsorbate structures and dynamics to extract these potentials quantitatively with unprecedented precision. These long-range effects have important consequences in catalysis and supramolecular assembly. Next, we will attempt to design these interactions to advantage to control the placement and transformation of atoms and molecules on surfaces.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

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

The great promise of single-molecule/assembly measurements is to understand how critical variations in structure, conformation, and environment relate to and control function.¹ New approaches to 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 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.

¹Electrons, Photons, and Force: Quantitative Single-Molecule Measurements from Physics to Biology, S. A. Claridge, J. J. Schwartz, and P. S. Weiss, ACS Nano 5, 693 (2011).

Nanoscale Control and Measurements for Biology, Medicine, & Neuroscience
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We pattern the exposed chemical functionality of flat and surfaces with exquisite precision, from the submolecular to the macroscopic scales, so as to control the biological, chemical, and physical properties of these intefaces. We have developed this strategy to identify, to measure, and to mimic biochemical interactions. In synthetic systems, by recording many thousands of simultaneous structural, functional, and spectroscopic measurements of single molecules and assemblies, we have shown the importance of understanding the heterogeneity of structure, conformation, and environment that influence function. We are therefore developing structural and functional measurements for biological systems that eliminate the averaging intrinsic to methods such as X-ray diffraction and nmr. This will enable elucidation of the key roles of structure and conformation in biological function and access to structures are not arranged periodically.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

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

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 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 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.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Nanoscale Optical Interactions in Precise Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Keywords: Optical interactions, self-assembly, spectroscopy, scanning probe microscopy.

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]. We have developed and applied new tools based on the scanning tunneling microscope (STM) to measure structure, function, and spectra simultaneously [3-5]. We are particularly interested in the interactions of photons with precisely assembled structures. Much previous work in this area has been limited by the absorption of light by the STM tip, resulting in heating and making quantitative measurements difficult. We have overcome this difficulty by coupling light evanescently into the tunneling junction using specially prepared substrates and a new set of STMs. The measured results of photoexcitation include photoconductivity and regioselective reaction [6,7]. We are applying this method to optimize molecules and materials for energy conversion and storage [8]. Related imaging spectroscopies we have developed give access to the cooperative action of assembled molecular motors and the identification and orientations of parts of molecules such as amyloid-forming oligopeptides. Complementary far-field measurements enable statistically significant optical measurements of function, dynamics, and chemical environment. We are applying the assembly strategies that we have developed for flat surfaces to curved and faceted substrates while measuring the environment, interactions, and dynamics of molecular probes designed for this purpose [7].

References:
[1] S. A. Claridge, W.-S. Liao, J. C. Thomas, Y. Zhao, H. Cao, S. Cheunkar, A. C. Serino, A. M. Andrews, and P. S. Weiss, From the Bottom Up: Dimensional Control and Characterization in Molecular Monolayers, Chemical Society Reviews, vol. 42, 2725-2745 (2013).
[2] Y. B. Zheng, B. K. Pathem, J. N. Hohman, J. C. Thomas, M. H. Kim, and P. S. Weiss, Photoresponsive Molecules in Well-Defined Nanoscale Environments, Advanced Materials, vol. 25, 302-312 (2013).
[3] A. M. Moore, S. Yeganeh, Y. Yao, S. A. Claridge, J. M. Tour, M. A. Ratner, and P. S. Weiss, ACS Polarizabilities of Adsorbed and Assembled Molecules: Measuring the Conductance through Buried Contacts, Nano, vol. 4, 7630 (2010).
[4] Y. B. Zheng, J. L. Payton, T.-B. Song, B. K. Pathem, Y. Zhao, H. Ma, Y. Yang, L. Jensen, A. K.-Y. Jen, and P. S. Weiss, Surface-Enhanced Raman Spectroscopy to Probe Photoreaction Pathways and Kinetics of Isolated Reactants on Surfaces: Flat vs. Curved Substrates, Nano Letters, vol. 12, 5362-5368 (2012).
[5] B. K. Pathem, S. A. Claridge, Y. B. Zheng, and P. S. Weiss, Molecular Switches and Motors on Surfaces, Annual Review of Physical Chemistry, vol. 64, 605-630 (2013). [6] M. H. Kim, J. N. Hohman, Y. Cao, K. N. Houk, H. Ma, A. K.-Y. Jen, and P. S. Weiss, Creating Favorable Geometries for Directing Organic Photoreactions in Alkanethiolate Monolayers, Science, vol. 331, 1312-1315 (2011).
[7] Y. B. Zheng, J. L. Payton, T.-B. Song, B. K. Pathem, Y. Zhao, H. Ma, Y. Yang, L. Jensen, A. K.-Y. Jen, and P. S. Weiss, Surface-Enhanced Raman Spectroscopy to Probe Photoreaction Pathways and Kinetics of Isolated Reactants on Surfaces: Flat vs. Curved Substrates, Nano Letters, vol. 12, 5362-5368 (2012).
[8] Visibly Transparent Polymer Solar Cells Produced by Solution Processing, C.-C. Chen, L. Dou, R. Zhu, T.-B. Song, Y. B. Zheng, C.-H. Chung, G. Li, P. S. Weiss, and Y. Yang, ACS Nano, vol. 6, 7185-7190 (2012).

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

Visualizing, Understanding, and Exploiting How Chemistry and Electronic Structure Are Coupled on Surfaces
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

A Career in Nanoscience (So Far)
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

I will discuss career choices and how to choose and to target scientific goals. I will discuss how we select specific problems and the thinking and arguing that goes into putting together the people, resources, and experiments to address them. My own route to nanoscience has been circuitous. My group is intentionally diverse in terms of background, with members from chemistry, engineering, materials science, mathematics, neuroscience, and physics. We teach each other languages and approaches. We bring together different perspectives to identify the key parts of the scientific problems we address.

Nanoscale Control and Measurements for Biology, Medicine, & Neuroscience
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We pattern the exposed chemical functionality of flat and surfaces with exquisite precision, from the submolecular to the macroscopic scales, so as to control the biological, chemical, and physical properties of these intefaces. We have developed this strategy to identify, to measure, and to mimic biochemical interactions. In synthetic systems, by recording many thousands of simultaneous structural, functional, and spectroscopic measurements of single molecules and assemblies, we have shown the importance of understanding the heterogeneity of structure, conformation, and environment that influence function. We are therefore developing structural and functional measurements for biological systems that eliminate the averaging intrinsic to methods such as X-ray diffraction and nmr. This will enable elucidation of the key roles of structure and conformation in biological function and access to structures are not arranged periodically.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

New Two-Dimensional Materials and Processing for Electronics and Biosensors
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095

We have developed a new method for preparing supported metal monolayers - chemical liftoff lithography. A reactive stamp is used to remove a self-assembled monolayer of molecules along with a supported monolayer of metal from a substrate. Both the supported metal monolayer and the exposed metal substrate are useful for further patterning. The supported metal monolayers can be straightforwardly patterned in two dimensions via control of the exposed surface chemistry, the pattern used for contact and reaction, and/or the patterning the substrate. This process can be used to prepare arrays of electronic devices and biosensors, including group IV and oxide semiconducting devices, as well as flexible, wearable, and conformal devices. We will discuss the lift-off process, the resulting materials, and the devices that can be made at high resolution with high throughput.

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, USA

The chemical, physical, and electronic 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 role that chemistry can play in making and optimizing precise contacts that preserve 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.

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

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 imaging and analyses 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 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.

Wavelet Transformations for the Segmentation of Self-Assembled Monolayers
Kevin Bui, Jacob Fauman, David Kes, and Leticia Torres, Department of Mathematics, UCLA, Los Angeles, CA 90095, USA

A Career in Nanoscience (So Far)
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

I will discuss career choices and how to choose and to target scientific goals. I will discuss how we select specific problems and the thinking and arguing that goes into putting together the people, resources, and experiments to address them. My own route to nanoscience has been circuitous. My group is intentionally diverse in terms of background, with members from chemistry, engineering, materials science, mathematics, neuroscience, oncology, and physics. We teach each other languages and approaches. We bring together different perspectives to identify the key parts of the scientific problems we address.

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, USA

The chemical, physical, and electronic 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 role that chemistry can play in making and optimizing precise contacts. 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.

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, USA

The chemical, physical, and electronic 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 role that chemistry can play in making and optimizing precise contacts that preserve 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.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules [1,2]. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity [3].

Opportunities for Nanoscience, Nanoscientists, and NanoCenters in Major Interdisciplinary Research Initiatives
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

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

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 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 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.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

Nanotools for Studying Microbiomes

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

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

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

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 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 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.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

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

Precise clusters offer a new set of building blocks with unique properties that can be leveraged both individually and in materials in which their coupling can be controlled by choice of linker, dimensionality, and structure. Initial measurements in both of these worlds have been made. Isolated adsorbed or tethered clusters are probed with low-temperature scanning tunneling microscopy and spectroscopy. Even closely related elements behave differently on identical substrates. Surprising spectral variations are found for repeated measurements of single isolated, tethered clusters. In periodic solids, precise clusters joined by linkers can be measured experimentally and treated theoretically with excellent agreement, in part due to the relatively weak coupling of the clusters. This coupling can be controlled and exploited to produce materials with tailored properties. Some of the rules for predicting these properties are being developed through these initial studies and the limit to which they can be applied is being explored.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

Nanoscience Approaches to Heterogeneity in Biological Systems
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 [1]. New approaches to 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 fusing spectroscopic imaging modalities [2,3] 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 [4]. Early examples will be discussed.

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

The chemical, physical, and electronic 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 role that chemistry can play in making and optimizing precise contacts that preserve 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.

Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule/assembly measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.

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, USA

The chemical, physical, and electronic 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 role that chemistry can play in making and optimizing precise contacts that preserve 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.

Ethics in publishing: Editorial and related experiences
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

At ACS Nano, as editors, we have encountered a variety of ethical issues. These came not only from inexperienced authors, but from all corners. Sitting at the crossroads of many fields gives us an interesting perspective on the approaches taken across fields and borders. A selection of these will be discussed.

Cage Molecule Self-Assembly
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA

We have shown that upright, symmetric cage molecules self-assembled on surfaces have simple domain and defect structures. Unlike linear molecules, such as alkanethiols on Au{111}, these cage molecules do not tilt and do not conformationally relax. The lattices of the cage molecules are determined by the projections of the cages on the surface. Thus, different isomers, such as carboranethiols on Au{111}, form identical lattice structures. These monolayers enable key tests of simple phenomena, such as the effects of dipole moment direction and amplitude. For example, molecules with dipoles parallel to the surface form nonpolar monolayers and outcompete molecules with dipoles normal the surface, which form polar monolayers. These properties can be measured both at the macroscopic and nanoscopic scales. We understand the enhanced stability of the nonpolar surfaces to aligned dipoles in the monolayers and set out to measure such effects. Using combinations of spectroscopic imaging and novel image analyses, we find that dipoles do align, even across domain boundaries. We use mixed self-assembled monolayers of carboranes to tune and to optimize the band alignment of organic electronic devices without changing the morphology of the active layer. We have also measured multifunctionalized cage molecules and shown that we can protonate and deprotonate thiol(ate)s to change the valency of attachment to the surface through simple reactions. The future of boron-containing cage molecules for self-assembly will be discussed further in terms of tailoring intermolecular interactions and in building off surfaces in three dimensions.

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7 February 2016

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