A5050473117- Gold and Silver Nanoparticles Synthesis and Applications
- Plasmonic and Surface Plasmon Research
- Spectroscopy Techniques in Biomedical and Chemical Research
- Advanced biosensing and bioanalysis techniques
- Electrochemical Analysis and Applications
- Spectroscopy and Quantum Chemical Studies
- Molecular Junctions and Nanostructures
- Crystal Structures and Properties
- Protein Interaction Studies and Fluorescence Analysis
- Biosensors and Analytical Detection
- Quantum Dots Synthesis And Properties
- Iron-based superconductors research
- Cultural Heritage Materials Analysis
- Spectroscopy and Chemometric Analyses
- Electrochemical sensors and biosensors
- Inorganic Chemistry and Materials
- Photochemistry and Electron Transfer Studies
- Catalytic Processes in Materials Science
- Near-Field Optical Microscopy
- Analytical Chemistry and Sensors
- Solid-state spectroscopy and crystallography
- Organic and Molecular Conductors Research
- Magnetism in coordination complexes
- Nonlinear Optical Materials Studies
- Advanced Condensed Matter Physics
Northwestern University
2014-2023
International Institute for Nanotechnology
2020
Northwest University
2004-2015
Oxonica (United States)
2010
Argonne National Laboratory
1997-2009
Art Institute of Chicago
2007-2009
University of Chicago
2004-2009
University of Illinois Urbana-Champaign
2006-2009
Getty Conservation Institute
2009
Shanghai Institute of Ceramics
2008
The discovery of the enhancement Raman scattering by molecules adsorbed on nanostructured metal surfaces is a landmark in history spectroscopic and analytical techniques. Significant experimental theoretical effort has been directed toward understanding surface-enhanced (SERS) effect demonstrating its potential various types ultrasensitive sensing applications wide variety fields. In 45 years since discovery, SERS blossomed into rich area research technology, but additional efforts are still...
Nanosphere lithography (NSL) is an inexpensive, simple to implement, inherently parallel, high throughput, materials general nanofabrication technique capable of producing unexpectedly large variety nanoparticle structures and well-ordered 2D arrays. This article describes our recent efforts broaden the scope NSL include strategies for fabrication several new structural motifs their characterization by atomic force microscopy. has also been demonstrated be well-suited synthesis size-tunable...
Surface enhanced Raman spectroscopy (SERS) is a powerful vibrational technique that allows for highly sensitive structural detection of low concentration analytes through the amplification electromagnetic fields generated by excitation localized surface plasmons. SERS has progressed from studies model systems on roughened electrodes to sophisticated studies, such as single molecule spectroscopy. We summarize current state knowledge concerning mechanism and new substrate materials. highlight...
Triangular silver nanoparticles (∼100 nm wide and 50 high) have remarkable optical properties. In particular, the peak extinction wavelength, λmax of their localized surface plasmon resonance (LSPR) spectrum is unexpectedly sensitive to nanoparticle size, shape, local (∼10−30 nm) external dielectric environment. This sensitivity LSPR nanoenvironment has allowed us develop a new class nanoscale affinity biosensors. The essential characteristics operational principles these nanobiosensors will...
This work utilizes dark-field optical microscopy to demonstrate the localized surface plasmon resonance λmax response of individual Ag nanoparticles formation a monolayer small-molecule adsorbates. The adsorption fewer than 60 000 1-hexadecanethiol molecules on single results in shift 40.7 nm. Additionally, kinetics nanoparticle was shown be comparable that other real-time sensor technologies.
In this article nanosphere lithography (NSL) is demonstrated to be a materials general fabrication process for the production of periodic particle array (PPA) surfaces having nanometer scale features. A variety PPA have been prepared using identical single-layer (SL) and double-layer (DL) NSL masks made by self-assembly polymer nanospheres with diameter, D=264 nm, varying both substrate material S M. examples shown here, was an insulator, semiconductor, or metal M metal, inorganic ionic...
In this work, we use dark-field microscopy to observe a new plasmon resonance effect for single silver nanocube in which the line shape has two distinct peaks when particles are located on glass substrate. The dependence of size and is characterized, it found that bluer peak higher figure merit chemical sensing applications than other particle shapes have been studied previously. Comparison measured results with finite difference time domain (FDTD) electrodynamics calculations enables us...
The wavelength corresponding to the extinction maximum, λmax, of localized surface plasmon resonance (LSPR) silver nanoparticle arrays fabricated by nanosphere lithography (NSL) can be systematically tuned from ∼400 nm 6000 nm. Such spectral manipulation was achieved using (1) precise lithographic control size, height, and shape, (2) dielectric encapsulation nanoparticles in SiOx. These results demonstrate an unprecedented level agility optical response throughout visible, near-infrared,...
ADVERTISEMENT RETURN TO ISSUEPREVFeaturesNEXTSurface-Enhanced Raman SpectroscopyChristy L. HaynesChristy HaynesMore by Christy Haynes, Adam D. McFarlandAdam McFarlandMore McFarland, and Richard P. Van DuyneRichard DuyneMore DuyneCite this: Anal. Chem. 2005, 77, 17, 338 A–346 APublication Date (Web):September 1, 2005Publication History Published online1 September 2005Published inissue 1 2005https://pubs.acs.org/doi/10.1021/ac053456dhttps://doi.org/10.1021/ac053456dnewsACS...
In this paper, we explore the optical properties of Ag nanoparticles chemically modified with alkanethiol self-assembled monolayers (SAMs) by measuring localized surface plasmon resonance (LSPR) spectrum using UV−vis extinction spectroscopy. For all experiments presented here, were fabricated technique nanosphere lithography (NSL) and had in-plane widths 100 nm out-of-plane heights 50 nm. We first demonstrate that unmodified are extremely susceptible to slight changes in 3-dimensional...
Silver and gold nanotriangles were fabricated by nanosphere lithography (NSL) their localized surface plasmon resonance (LSPR) spectra measured UV−vis extinction spectroscopy. It is demonstrated that the short range (viz., 0−2 nm) distance dependence of electromagnetic fields surround these nanoparticles when resonantly excited can be systematically tuned changing size, structure, composition. This accomplished measuring shift in peak wavelength, λmax, LSPR caused adsorption hexadecanethiol...
A detailed wavelength-scanned surface-enhanced Raman excitation spectroscopy (WS SERES) study of benzenethiol adsorbed on Ag nanoparticle arrays, fabricated by nanosphere lithography (NSL), is presented. These NSL-derived array surfaces are both structurally well-characterized and extremely uniform in size. The WS SERES spectra correlated, spatially spectrally, with the corresponding localized surface plasmon resonance (LSPR) arrays. scattering (SERS) were measured two wavelength ranges: (1)...
The plasmonic properties of single silver triangular nanoprisms are investigated using dark-field optical microscopy and spectroscopy. Two distinct localized surface plasmon resonances (LSPR) observed. These assigned as in-plane dipolar quadrupolar excitations electrodynamic modeling based on the discrete dipole approximation (DDA). resonance is found to be very intense, its peak wavelength extremely sensitive height, edge length, tip sharpness nanoprism. In contrast, intensity quadrupole...
We present here a detailed study of the specific nanoparticle structures that give rise to single-molecule surface-enhanced Raman scattering (SMSERS). A variety are observed, but simplest dimers Ag nanocrystals. chose one these for using electrodynamics calculations and found electromagnetic SERS enhancement factors 10(9) easily obtained consistent with activity.
A nanoscale optical biosensor based on localized surface plasmon resonance (LSPR) spectroscopy has been developed to monitor the interaction between antigen, amyloid-beta derived diffusible ligands (ADDLs), and specific anti-ADDL antibodies. Using sandwich assay format, this nanosensor provides quantitative binding information for both antigen second antibody detection that permits determination of ADDL concentration offers unique analysis aggregation mechanisms putative Alzheimer's disease...
The localized surface plasmon resonance (LSPR) of oxide-free Cu nanoparticles fabricated by nanosphere lithography is examined UV−vis extinction spectroscopy and electrodynamics theory. LSPR the significantly affected presence copper oxides removal oxide species yields a dramatic difference in observed LSPR. From comparison Cu, Ag, Au similar geometry, we conclude that displays an intense narrow peak comparable to Ag Au.
Understanding the detailed relationship between nanoparticle structure and activity remains a significant challenge for field of surface-enhanced Raman spectroscopy. To this end, structural optical properties individual plasmonic nanoantennas comprised Au assemblies that are coated with organic reporter molecules encapsulated by SiO(2) shell have been determined using correlated transmission electron microscopy (TEM), dark-field Rayleigh scattering microscopy, (SERS) finite element method...
Nanosphere lithography (NSL) is an inexpensive, inherently parallel, high-throughput, and materials-general nanofabrication technique capable of producing well-ordered 2D periodic particle arrays nanoparticles. This paper focuses on the synthesis size-tunable silver nanoparticle by nanosphere their structural characterization atomic force microscopy (AFM). The in-plane diameter, a, Ag nanoparticles was tuned from 21 to 126 nm systematic variation D. Similarly, out-of-plane height, b, 4 47...
After its discovery more than 30 years ago, surface-enhanced Raman spectroscopy (SERS) was expected to have major impact as a sensitive analytical technique and tool for fundamental studies of surface species. Unfortunately, the lack reliable reproducible fabrication methods limited applicability. In recent years, SERS has enjoyed renaissance, there is renewed interest in both fundamentals applications SERS. New techniques nanofabrication, design substrates that maximize electromagnetic...
The localized surface plasmon resonance (LSPR) nanosensor based on the optical properties of Ag nanotriangles is shown to aid in understanding interaction between amyloid β-derived diffusible ligands (ADDL) and anti-ADDL antibody, molecules possibly involved development Alzheimer's disease. By varying concentration a confined binding constant 3.0 × 107 M-1 for ADDLs anti-ADDLs was measured. Influences Cr, nanoparticle adhesion layer, will be limiting factor sensitivity this assay. This first...