Naomi J. Halas - US grants

We propose to further our initial investigations of carrier dynamics in solid C60 begun at Rice, using time-resolved optical methods to study both carrier relaxation and transport mechanisms in this material. Also, we plan to investigate semiconductor interface electronic structure and its effect on bulk carrier dynamics near the surface.

A X-ray facility consisting of a rotating anode X-ray generator and two different diffraction systems on opposite sides of the generator will be acquired with the funds from the Academic Research Infrastructure Program. One diffraction unit will be a 4-circle diffractometer for accurate lattice parameter and structural determinations of thin films, single crystals, and powder samples. A second diffraction unit will involve an advanced 2-dimensional array detector for small angle X-ray scattering from biological and thin film samples. The facility will be employed to study: 1) the structure of lanthanide endohedral fulleneres and fullerene-encapsulated metal clusters, the study of low-dimensional mixed-valence compounds associated with superconduct-ivity and and charge density waves, 3) various properties of the unique van der Waals C60 solids, 4) magnetic multilayer thin films, 5) diamond thin films prepared by chemical vapor deposition and ion- implantation techniques, 6) growth of thin ferroelectric films on crystalline and amorphous substrates, 7) genetic features of regulatory proteins and the biochemistry and biology of repressor proteins, 8) the thermodynamic properties of natural minerals. A modern X-ray facility with two types of diffractometers will be employed to study a diverse range of materials by scientists in the Chemistry, Electrical Engineering, Biosciences, Materials Science and Geology Departments. The materials studied will include fullerenes, diamond thin films, repressor proteins, magnetic multilayers, ferroelectric thin films, and natural minerals.

9802892
Smalley
This award provides partial support for the acquisition of equipment to provide Rice University researchers with a state-of-the-art ultrahigh vacuum, variable-temperature scanning tunneling/atomic force microscope instrument. This instrument will address the needs for nanoscale imaging, localized spectroscopy, and single molecule device fabrication and transport measurement capabilities for a cluster of faculty members in the Physics, Chemistry, and Electrical and Computer Engineering Departments. A primary focus for this instrument is the study of fullerene nanotubes in a range of scientific and technological contexts.

The system will allow the following research activities:

1) imaging and spectroscopy of fullerene nanotubes and other nanoparticles of interest,
2) assembly of single-molecule and nanoparticle-based device structures,
3) characterization of hybrid e-beam lithography/molecular self-assembly device fabrication methods,
4) fabrication, characterization, and imaging applications of fullerene STM tips: C60- adsorbed STM tips, and fullerene nanotube AFM/STM tips,
5) structural imaging and spectroscopic investigations of functionalized fullerene nanotubes and nanotube defects using C60-adsorbed STM tips,
6) temperature-dependent nanoscale imaging and analysis of the phase transitions and structural transformations in nanosized polymers.

This instrument will be the only ultrahigh vacuum or variable temperature STM/AFM instrument at Rice University. It will therefore provide significant new experimental capabilities, enhancing the ongoing programs of several research groups as well as providing a state-of-the-art nanoscale facility for junior faculty with growing research programs.
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9801707
Halas
This proposal addresses the use of metal nanoshells and metal-dielectric nanoparticles assemblies for the "nanoengineering" of a wide variety of unique and potentially technologically important optical properties into both materials and devices. The central goal is to apply these enhancement of existing materials and the development of new materials and devices. This is a multidisciplinary effort composed of nanopartical synthesis, film and device preparation, a variety of optical and physical spectroscopies and measurements, the theoretical analysis. The specific topics of focus are:

- the development of metal nanoshell-based materials as infrared absorbers and NLO materials, and as solar absorbing/scattering materials;

- the incorporation of metal nanoshells into conducting polymers where the metal nanoshell resonances are judiciously placed in interact selectively with specific excitations of the material;

- the addition of photoluminescent species into the dielectric core of metal nanoshells, to characterize the effect of the metallic "nanocavity" on the optically active species inside;

- the fabrication of layered device structures incorporating metal nanoshells, to characterize plasmon-induced hot electron-based photoconductivity in these devices;

- to exploit the intense local field of the metal nanoshell plasmon by incorporating the nanostructure at the apex of a Scanning Tunneling Microscop tip, for optically addressable probe tip applications;

- to develop nanoparticle assemblies as terahertz-resonant materials and as an experimental testbed for studying and controlling plasmon-plasmon interactions in well-characterized geometries.

Although highly multidisciplinary in scope, the work described in this proposal is consistent with the demonstrated expertise of the Principal Investigator, her research group, and her current collaborators. This integrated combination of chemical synthesis, optical and electron spectroscopies, scanning probe microscopies, and theory defines and exciting research atmosphere in which graduate students propsper and provides a successful, innovative paradigm for applied research.
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9821049
Halas
A new approach to biosensing utilizing nanoparticles with specifically engineered electromagnetic resonances is proposed. Two specific goals are targeted: (I) the fabrication and demonstration of an all optical in vivo glucose sensor, and (2) The development of a streamlined, all optical bioassay for the detection of plasma proteins in whole blood. Metal Nanoshells, composite nanoparticles consisting of a dielectric core and an ultrathin gold shell, possess a strong plasmon excitation whose resonant frequency is controlled by the particle core diameter and shell thickness. By varying the nanoparticle's core/shell ratio, this resonance may be positioned at any wavelength across much of the visible and near infrared regions of the spectrum. When the nanoshell plasmon is resonant with a Raman excitation laser, enormous surface enhanced Raman scattering (SERS) enhancements have been observed from molecules adsorbed to the individual nanoshells. These enhancements occur without contributions from nanoparticle aggregation, as is typical with solid metal nanoparticle SERS enhancements. This effect provides a highly sensitive, high information content all-optical probe of molecular species in the local vicinity of individual nanoparticles suspended in a solution or other media. In addition, the plasmon resonance may be placed in a spectral "water window" of high infrared transmissivity in biological fluids and tissue, facilitating simple in vitro and in vivo sensing designs. Protein-conjugated nanoshell species, synthesized using the many well-established protocols of immunogold, will be utilized as specific functional agents in the development of new optically-based biosensing applications. Both sensor projects consist of bioconjugate-nanoshell attachment and activity studies, a series of nanoshell SERS-enhanced Raman spectroscopic studies for the biochemical species and reactions of interest, and characterization of the Raman-based monitors versus standard calibration methods. In the case of the glucose sensor development these investigations will be followed by incorporation of the bioconjugate-nanoshell species into hydrogel media and in viva in the final stage. This project provides an exciting, goal oriented interdisciplinary series of studies that combines expertise in nanoparticle synthesis, immunochemistry, Raman and infrared spectroscopy, and quantitative and statistical analysis. The work described in this proposal is consistent with the demonstrated expertise of the two Principal Investigators. This project will stimulate and unite graduate students in the disciplines of electrical engineering, applied physics, bioengineering and biochemistry toward goals of major technical and societal impact.
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0221544
Drezek
The proposed project leverages recent advances in nanoparticle technologies to develop innovative contrast agents which can be optically interrogated using noninvasive approaches and targeted to specific molecular signatures of disease. The contrast agents proposed - nanoshells and nanoemitters - possess ideal optical and chemical properties for optical imaging. The optical response of these particles can be precisely and systematically varied over a broad band including the visible and infrared spectral regions. The extremely agile. tunabilityof the optical resonance is completely unique to nanoshells: in no other molecular or nanoparticle structure can the resonance of the optical extinction properties be systematically. designed. Moreover, the nanoparticles are highly biocompatible and proteins (such as antibodies) are readily conjugated to their surfaces. To develop the potential of nanoparticles as contrast agents for optical imaging, the investigators will study a novel class of exogenous contrast agents designed and optimized to address the clinically important problem of detection of pre.invasive neoplasias.

Abstract

The objective of this research is the development of a new type of a scanning local probe microscope capable of obtaining chemical information with nanoscale resolution and to utilize this microscope in a wide range of applications pursued by different research groups at Rice University. The microscope will consist of a metallodielectric nanoparticle mounted or integrated as an Atomic Force Microscope tip (AFM) tip. The nanoparticle will be designed to have plasmon resonant response in the infrared region of the spectrum (2.7 -10 microns in wavelength; 1000-3600 cm-1). The strong electromagnetic field enhancements associated with the excitations of plasmons in the probe tip will dramatically enhance the cross sections for infrared excitation of dipole active vibrational modes in the tip-sample junction

This project will result in a new and unique nanoscale spectroscopic tool that will be useful across a very broad range of technical applications, such as fundamental nanoscale studies in the physical and chemical sciences, a valuable new imaging probe in the life sciences, and a unique, breakthrough sensor technology for environmental analysis and detection of trace chemical species. The highly collaborative multidisciplinary instrument development team consists of researchers in the departments of Electrical and Computer Engineering, Chemistry, Physics, and Bioengineering. Two courses will be developed during this project addressing the theoretical and experimental aspects of nanoscale instrument component design and fabrication. A large number of users for this instrument have been identified within the Rice science and enginee

This award is in support of the Research Experiences for Undergraduates site located the Rice Quantum Institute at Rice University. The REU program conducted by the Rice Quantum Institute (RQI) brings students from outside universities to Rice University for a ten-week interdisciplinary summer research program. Each student works directly within the research group of a faculty mentor from science and engineering departments within RQI. Each project is designed to be part of a long-range research program by the faculty mentor, but individual to the student and manageable within ten weeks. The students are collectively exposed to different disciplines by contact with a variety of research groups in other labs, weekly seminars by Rice grad students and frequent scientific and social interactions (as well as joint housing) with the other REU students. In mid-session, the students present brief computer presentations to each other and the PI of the context, goals, hurdles and long-range expected yield of their projects. During the final week, written reports are turned in, exit interviews are performed, and, on the last day, students present their work at the RQI Colloquium. This annual event, which assembles a large audience made up of REU students, of research groups and others from Rice, as well as interested outsiders from neighboring schools and industries, showcases research going on within the Institute. This site is co-funded by the Department of Defense in partnership with the NSF REU program, and by the Physics Division, the Division of Materials Research, and the Chemistry Division within the Directorate for Mathematical and Physical Sciences.

Research Objectives and Approaches: The objective of this research is to develop an integrated instrument for the fabrication and characterization of plasmonic nanostructures and nanodevices. The approach combines a scanning electron microscope with imaging, localized etching and deposition, and lithography capabilities, with optical spectroscopies, cathodoluminescence, and electrical characterization.

Intellectual Merit:

The proposed platform integrates structural, optical, and electrical characterization to a level substantially above any current commercial or custom-built system. This system will allow the development of active plasmon-based structures and devices, with direct fabrication and characterization. The developmental challenge in this project is the integration of the variety of techniques into one platform and the leveraging of this combined capability to achieve new strategies for developing active plasmonic systems.

Broader Impact:

The availability of this platform will greatly enhance current experimental capabilities in plasmonics, nanoscale photonics and optoelectronics, advancing our understanding of the physical principles upon which their behavior is based. This will enable new applications of plasmonic systems currently limited by joint challenges in the fabrication and characterization of active plasmonic nanostructures.

Rice currently supports an IGERT program in Nanophotonics, a professional master?s program in Nanoscale Physics and an undergraduate REU program ?Conjunto? aimed at underrepresented minority students. The availability of the proposed instrument would provide an unmatched opportunity for all students to participate in research in nanophotonics. The cathodoluminescence capability is not available even as a standalone instrument in the Houston area. This experimental system will be welcomed by the growing nanophotonics research community in southeast Texas.

This award supports a one year renewal of the Research Experience for Undergraduates (REU) site at the Rice Quantum Institute at William Marsh Rice University. The award will support students for ten weeks of summer research in topics potentially including chemistry, physics, electrical engineering, chemical engineering, materials science, and bioengineering. Each student becomes involved in cutting-edge research by joining an individual research group and working with graduate students, postdocs and faculty supervisors. The students will form a cohesive group through joint housing, weekly interdisciplinary scientific seminars, and weekly social activities. These activities also include laboratory safety training and participation in an online course in ethical and responsible scientific conduct. In mid-session, the students will present brief computer presentations of their work to each other and the PI. In the seventh week, students will construct abstracts for their projects. During the last week students will turn in written reports, design and assemble poster presentations on their research, then present their posters alongside the other undergraduate participants in an extremely well-attended session of the Annual RQI Colloquium. There will also be a lunch meeting with faculty from various disciplines to discuss strategies for graduate school, the admissions process, and other professional/technical career options. This award is co-funded by the Division of Physics and the Division of Chemistry in the Directorate for Mathematical and Physical Sciences.

This award supports the renewal of the Research Experience for Undergraduates (REU) program in Physics at William Marsh Rice University. The award will support students for ten weeks of summer research in topics potentially including chemistry, physics, electrical engineering, chemical engineering, materials science, and bioengineering. Each student becomes involved in cutting-edge research by joining an individual research group and working with graduate students, postdocs and faculty supervisors. The students will form a cohesive group through joint housing, weekly interdisciplinary scientific seminars, and weekly social activities. These activities also include laboratory safety training and participation in an online course in ethical and responsible scientific conduct. In mid-session, the students will present brief computer presentations of their work to each other and the PI. In the seventh week, students will construct abstracts for their projects. During the last week students will turn in written reports, design and assemble poster presentations on their research, then present their posters alongside the other undergraduate participants in an extremely well-attended session of the Annual RQI Colloquium. There will also be a lunch meeting with faculty from various disciplines to discuss strategies for graduate school, the admissions process, and other professional/technical career options.

With this award from the Major Research Instrumentation (MRI) program and support from the Chemistry Research Instrumentation (CRIF) program, Professor Isabell Thommann from the William Marsh Rice University will acquire parts to asssemble a femtosecond time-resolved nanophotonic scanning probe microscope. This will make it possible to study nanostructured materials synthesized for energy and sustainability applications with unprecedented spatial and temporal resolution. These measurements will allow probing the chemical and physical properties of the materials to help understand energy flow and charge carrier dynamics in hybrid nanostructured materials. This will help to address challenges in the production of large scale applications of these materials. The acquisition will be a multiuser instrument used by researchers at the university and also for new collaborations in the Houston area, and nationally. It will strengthen the outreach efforts at the university to high school teachers and students.

The award is aimed at enhancing research and education at all levels, especially in areas such as (a) studying charge separation kinetics in all-conjugated block copolymer thin films; (b) investigating carrier dynamics in two-dimensional materials and devices for energy; (c) using time-resolved photoluminescence as a probe of hot electron dynamics; (d) studying hot electron dynamics in plasmonic antennas; (e) carrying out spatiotemporal investigations of photocatalytic virus inactivation; (f) studying photocatalytic water splitting on nanostructured cobalt oxide by time-resolved tip-enhanced Raman scattering; (g) investigating photocatalytic water splitting on plasmonic photoelectrodes.

Title: A Nanosystems Engineering Research Center for Nanotechnology Enabled Water Treatment.

Access to safe drinking water is a basic need for all life on the planet. It is a grand challenge linked to public health, energy production, and sustainable development. This is not just a need in the developing world. Over 40 million Americans are not connected to a municipal water system and rely on the quality of the water available from wells. The quality of this water varies with location and climate change exacerbates fresh water scarcity. The technologies that result from the research of this center will broaden access to clean drinking water with a variety of potential sources (e.g. groundwater from wells, salt water, brackish water, or recycled industrial water). The modular systems that will be designed will address drinking water from the scale of a household, to a neighborhood to a remote town. These technologies will also find application to help people get drinking water during natural disasters. In addition to drinking water, the Center will improve the water "footprint" of oil and gas exploration and production operations by helping to increase the quality of water cleanup for reuse and recycle. The environmental impact of water use in these industrial settings will be improved, saving energy and water resources. Students trained in this Center will have a multidisciplinary, team-based research experience with the skills needed to translate their research to a broad set of stakeholders (e.g., industrial organizations, governmental organizations, and citizens) that lack a secure source of clean water.

The ERC is led by Rice University, with partners at Arizona State University, University of Texas-El Paso and Yale University. The Center's use of nanotechnology will allow the design and manufacture of multifunctional nanomaterials to adsorb a wide variety of pollutants including oxo-anions, total dissolved solids, nitrates, salts, organics, foulants, scalants, viruses and microbes. These nanomaterials will be immobilized in membranes that are packaged into system modules. The use of modules offers flexibility of targeted pollutant(s) and end-use application capacity or scale of delivered water rate. Novel photonic, electronic, catalytic, and magnetic engineered nanomaterials (ENMs) will introduce new approaches to transform water treatment from a large, chemical- and energy-intensive process toward compact physical and catalytic systems. These innovations will benefit multiple stakeholders, from rural communities and locations hit by natural disasters to hydraulic fracturing oil and gas sites, where reuse of produced waters minimizes regional environmental impacts. The Center's innovative technologies are founded on rigorous basic research. Component technologies include fouling-resistant, high-permeability membranes that use ENMs for surface self-cleaning and biofilm control; capacitive deionization with highly conductive and selective electrodes to remove scalants (divalent ions); rapid magnetic separation of paramagnetic nanosorbents for easy reuse; nanophotonics-enabled direct solar membrane distillation for low-energy desalination; disinfection and advanced oxidation/reduction using nanocatalysts; and template-assisted nanocrystallization for scaling control. Fundamental research on ENM interactions with water pollutants and substrate materials; integrated unit processes that immobilize, support, or recover ENMs; and safety by design demonstrated in testbeds will ensure that the Center's systems are resilient, economical, and highly efficient.

The identification of small molecules in our atmosphere, water supply, and exhaled breath or body fluids, is an extremely important capability with applications ranging from identification of dangerous environmental toxins to early-stage disease detection. The methods that are currently available to perform this type of chemical identification, however, require large, expensive and sensitive instruments, are available only in laboratory settings, and are based on decades-old technologies. The work enabled by this research grant aims to combine two recent research advances to develop a new approach for identifying small molecules. This work could ultimately provide chemical identification capabilities in ultracompact geometries that could be used in a variety of non-laboratory settings. The ability to rapidly detect and accurately identify molecules in the clinic or in the field has wide-ranging has applications in areas ranging from agriculture, pharmaceuticals, food quality control, and medical screening, including brain function. This approach could ultimately be used for identifying a plurality of molecules at a fully integrated, chip-based level of detection compatible, ultimately, with cloud-based processing and smart-phone-based data acquisition. The cross-cutting, multidisciplinary concepts central to this proposal provide a broad opportunity for student education at the high school, undergraduate, and graduate student level.
Technical Description:
The goal of this proposal is to develop highly compact infrared spectroscopic capabilities based on narrowband nanoantenna-diodes for near-infrared molecular spectroscopy. Two independent research advances in nanophotonics were recently pioneered which, when combined, are ideally suited to address this goal. They are: (1) the demonstration of optically active nanoantenna-diodes, where carriers are generated by the decay of photoexcited surface plasmons in resonant metallic nanoantennas, then injected into the conduction band of the adjacent semiconductor, and (2) the development of infrared nanoantennas tuned to the resonant vibration frequencies of specific chemical functional groups. By merging these two concepts, narrowband, infrared active nanoantenna-diodes for the spectroscopic identification of small molecules with direct electrical readout will be created. Efforts will focus on the development of nanoantenna-diodes with enhanced responsivities and quantum efficiencies, through the implementation of gain, and on lineshape control of the nanoantenna-diode spectral response, to ultimately resolve molecular spectral lines in the near-infrared region of the spectrum. This approach would ultimately eliminate the need for near-infrared photodetectors based on costly materials, along with the bulky dispersive optics and large optical path lengths required in conventional infrared spectroscopy for wavelength discrimination.

The broader impact/commercial potential of this I-Corps project is addressing the increasing demand for sustainable water purification and cost-effective phase separation with an energy-efficient, economical, portable and scalable solution. More than a billion people around the world lack access to clean drinking water. Most of the existing technologies for water purification and phase separation mainly use energy from conventional fuels increasing their operating cost and limiting their application. The proposed technology of Nanophotonics-enabled Solar Membrane Distillation (NESMD) uses solar energy to vaporize water and potentially other liquids of interest. NESMD system is energy-efficient, portable and can be scaled in size making it suitable for household, commercial and industrial water purification. Cost-effective phase separation with NESMD can be attractive for petroleum and related industries as well.

This I-Corps project focuses on electricity-free water purification and phase separation. Nanophotonics-enabled Solar Membrane Distillation (NESMD) system consists of a polymer membrane coated with light-absorbing carbon-based nanomaterials which efficiently absorb incident sunlight. The capability of converting light into heat within a thin layer on top of a semipermeable membrane allows an efficient local conversion of liquid to its vapor phase. This membrane can be used in contact with saline/polluted water or a mixture of organic solvents allowing the heat from the absorbed sunlight to induce vaporization through the membrane separating the liquid of interest from non-volatile components such as salts, heavy metals, bacteria or other liquids. Proof-of-concept lab-scale studies of the NESMD system show efficient water purification with more than 99.5% salt rejection. Through this I-Corps project the team wants to further assess and investigate the value of this technology for water purification and phase separation market.