The Experts below are selected from a list of 29799 Experts worldwide ranked by ideXlab platform
Richard P Van Duyne - One of the best experts on this subject based on the ideXlab platform.
-
advances in Localized Surface Plasmon resonance spectroscopy biosensing
Nanomedicine: Nanotechnology Biology and Medicine, 2011Co-Authors: Laura B Sagle, Laura K Ruvuna, Julia A Ruemmele, Richard P Van DuyneAbstract:In recent years, Localized Surface Plasmon resonance (LSPR) spectroscopy advancements have made it a sensitive, flexible tool for probing biological interactions. Here, we describe the basic principles of this nanoparticle-based sensing technique, the ways nanoparticles can be tailored to optimize sensing, and examples of novel LSPR spectroscopy applications. These include detecting small molecules via protein conformational changes and resonance LSPR spectroscopy, as well as coupling LSPR with mass spectrometry to identify bound analytes. The last few sections highlight the advantages of single nanoparticle LSPR, in that it lowers limits of detection, allows multiplexing on the nanometer scale, and enables free diffusion of sensors in solution. The cases discussed herein illustrate creative ways that LSPR spectroscopy has been improved to achieve new sensing capabilities.
-
gas sensing with high resolution Localized Surface Plasmon resonance spectroscopy
Journal of the American Chemical Society, 2010Co-Authors: Julia M Bingham, Jeffrey N Anker, Lauren E Kreno, Richard P Van DuyneAbstract:We report the first inert gas sensing and characterization studies based on high-resolution Localized Surface Plasmon resonance (HR-LSPR) spectroscopy. HR-LSPR was used to detect the extremely small changes (<3 × 10−4) in bulk refractive index when the gas was switched between He(g) and Ar(g) or He(g) and N2(g). We also demonstrate submonolayer sensitivity to adsorbed water from exposure of the sensor to air (40% humidity) versus dry N2(g). These measurements significantly expand the applications space and characterization tools for Plasmonic nanosensors.
-
resonance Localized Surface Plasmon spectroscopy sensing substrate and inhibitor binding to cytochrome p450
Journal of Physical Chemistry C, 2008Co-Authors: Jing Zhao, Aditi Das, George C Schatz, Stephen G Sligar, Richard P Van DuyneAbstract:A sensing method based on resonance Localized Surface Plasmon spectroscopy was developed for low molecular weight substrate and inhibitor molecules binding to heme proteins. Cytochrome P450 proteins have Soret and Q absorption bands in the visible wavelength region. The coupling between the molecular resonance of P450 and the Localized Surface Plasmon resonance (LSPR) of functionalized silver nanoparticles leads to a highly wavelength-dependent LSPR response. Binding of substrate (e.g., camphor) or inhibitor (e.g., imidazole) molecules to a cytochrome P450 causes the absorption band of cytochrome P450 shift to shorter or longer wavelengths, respectively. By monitoring the Localized Surface Plasmon resonance (LSPR) of the nanosensors, the binding of camphor/imidazole to a nanoparticle whose Surface is modified with cytochrome P450 protein leads to a wavelength-dependent blue/red shift in the LSPR. The magnitude of the LSPR shift induced by camphor or imidazole is consistent with the Soret band wavelength shift observed in P450 in solution.
-
Localized Surface Plasmon resonance spectroscopy and sensing
Annual Review of Physical Chemistry, 2007Co-Authors: Katherine A. Willets, Richard P Van DuyneAbstract:Localized Surface Plasmon resonance (LSPR) spectroscopy of metallic nanoparticles is a powerful technique for chemical and biological sensing experiments. Moreover, the LSPR is responsible for the electromagnetic-field enhancement that leads to Surface-enhanced Raman scattering (SERS) and other Surface-enhanced spectroscopic processes. This review describes recent fundamental spectroscopic studies that reveal key relationships governing the LSPR spectral location and its sensitivity to the local environment, including nanoparticle shape and size. We also describe studies on the distance dependence of the enhanced electromagnetic field and the relationship between the Plasmon resonance and the Raman excitation energy. Lastly, we introduce a new form of LSPR spectroscopy, involving the coupling between nanoparticle Plasmon resonances and adsorbate molecular resonances. The results from these fundamental studies guide the design of new sensing experiments, illustrated through applications in which researchers use both LSPR wavelength-shift sensing and SERS to detect molecules of chemical and biological relevance.
-
Localized Surface Plasmon resonance biosensors
Nanomedicine: Nanotechnology Biology and Medicine, 2006Co-Authors: Jing Zhao, Amanda J Haes, Xiaoyu Zhang, Chanda Ranjit Yonzon, Richard P Van DuyneAbstract:In this review, the most recent progress in the development of noble metal nano-optical sensors based on Localized Surface Plasmon resonance (LSPR) spectroscopy is summarized. The sensing principle relies on the LSPR spectral shifts caused by the surrounding dielectric environmental change in a binding event. Nanosphere lithography, an inexpensive and simple nanofabrication technique, has been used to fabricate the nanoparticles as the LSPR sensing platforms. As an example of the biosensing applications, the LSPR detection for a biomarker of Alzheimer's disease, amyloid-derived diffusable ligands, in human brain extract and cerebrospinal fluid samples is highlighted. Furthermore, the LSPR sensing method can be modified easily and used in a variety of applications. More specifically, a LSPR chip capable of multiplex sensing, a combined electrochemical and LSPR protocol and a fabrication method of solution-phase nanotriangles are presented here.
Amanda J Haes - One of the best experts on this subject based on the ideXlab platform.
-
Localized Surface Plasmon resonance biosensors
Nanomedicine: Nanotechnology Biology and Medicine, 2006Co-Authors: Jing Zhao, Amanda J Haes, Xiaoyu Zhang, Chanda Ranjit Yonzon, Richard P Van DuyneAbstract:In this review, the most recent progress in the development of noble metal nano-optical sensors based on Localized Surface Plasmon resonance (LSPR) spectroscopy is summarized. The sensing principle relies on the LSPR spectral shifts caused by the surrounding dielectric environmental change in a binding event. Nanosphere lithography, an inexpensive and simple nanofabrication technique, has been used to fabricate the nanoparticles as the LSPR sensing platforms. As an example of the biosensing applications, the LSPR detection for a biomarker of Alzheimer's disease, amyloid-derived diffusable ligands, in human brain extract and cerebrospinal fluid samples is highlighted. Furthermore, the LSPR sensing method can be modified easily and used in a variety of applications. More specifically, a LSPR chip capable of multiplex sensing, a combined electrochemical and LSPR protocol and a fabrication method of solution-phase nanotriangles are presented here.
-
Localized Surface Plasmon resonance spectroscopy near molecular resonances
Journal of the American Chemical Society, 2006Co-Authors: Amanda J Haes, Jing Zhao, George C Schatz, Shengli Zou, Richard P Van DuyneAbstract:The peak location of the Localized Surface Plasmon resonance (LSPR) of noble metal nanoparticles is highly dependent upon the refractive index of the nanoparticles' surrounding environment. In this study, new phenomena are revealed by exploring the influence of interacting molecular resonances and nanoparticle resonances. The LSPR peak shift and line shape induced by a resonant molecule vary with wavelength. In most instances, the oscillatory dependence of the peak shift on wavelength tracks with the wavelength dependence of the real part of the refractive index, as determined by a Kramers−Kronig transformation of the molecular resonance absorption spectrum. A quantitative assessment of this shift based on discrete dipole approximation calculations shows that the Kramers−Kronig index must be scaled in order to match experiment.
-
a unified view of propagating and Localized Surface Plasmon resonance biosensors
Analytical and Bioanalytical Chemistry, 2004Co-Authors: Amanda J Haes, Richard P Van DuyneAbstract:The intense colors of noble metal nanoparticles have inspired artists and fascinated scientists for hundreds of years. In this review, we describe refractive index sensing platforms based on the tunability of the Localized Surface Plasmon resonance (LSPR) of arrays of silver nanoparticles and of single nanoparticles. Specifically, the color associated with single nanoparticles and Surface-confined nanoparticle arrays will be shown to be tunable and useful as platforms for chemical and biological sensing. Finally, the LSPR nanosensor will be compared to traditional, flat Surface, propagating Surface Plasmon resonance sensors.
-
preliminary studies and potential applications of Localized Surface Plasmon resonance spectroscopy in medical diagnostics
Expert Review of Molecular Diagnostics, 2004Co-Authors: Amanda J Haes, Richard P Van DuyneAbstract:Miniature optical sensors that specifically identify low concentrations of environmental and biological substances are in high demand. Currently, there is no optical sensor that provides identification of the aforementioned species without amplification techniques at naturally occurring concentrations. Recently, it has been demonstrated that triangular silver nanoparticles have remarkable optical properties and that their enhanced sensitivity to their nanoenvironment has been used to develop a new class of optical sensors using Localized Surface Plasmon resonance spectroscopy. The examination of both model and nonmodel biological assays using Localized Surface Plasmon resonance spectroscopy will be presented in this review. It will be demonstrated that the use of a Localized Surface Plasmon resonance nanosensor rivals the sensitivity and selectivity of, and provides a low-cost alternative to, commercially available sensors.
-
nanoscale optical biosensors based on Localized Surface Plasmon resonance spectroscopy
Proceedings of SPIE - The International Society for Optical Engineering, 2003Co-Authors: Amanda J Haes, Richard P Van DuyneAbstract:The Ag nanoparticle based Localized Surface Plasmon resonance (LSPR) nanosensor yields ultrasensitive biodetection with extremely simple, small, light, robust, and low-cost instrumentation. Using LSPR spectroscopy, the model system, biotinylated Surface-confined Ag nanotriangles, was used to detect less than one picomolar up to micromolar concentrations of streptavidin. Additionally, the monitoring of anti-biotin binding to biotinylated Ag nanotriangles exhibited that the system could be used as a solution immunoassay. The system was rigorously tested for nonspecific binding interactions and was found to display virtually no adverse results. These results represent important new steps in the development of the LSPR nanobiosensor for applications in medical diagnostics, biomedical research, and environmental science.
Chien Chou - One of the best experts on this subject based on the ideXlab platform.
-
Localized Surface Plasmon coupled fluorescence fiber optic biosensor for alpha fetoprotein detection in human serum
Biosensors and Bioelectronics, 2009Co-Authors: Ying-feng Chang, Ran-chou Chen, Shuchen Chao, Lichen Su, Yingchang Li, Chien ChouAbstract:In this study, we demonstrated that the fiber-optic biosensor based on Localized Surface Plasmon coupled fluorescence (LSPCF) is capable of detecting alpha-fetoprotein (AFP) in human serum. The sensitivity of LSPCF fiber-optic biosensor is not only enhanced but also the specific selectivity is improved since the fluorophores are excited by the Localized Surface Plasmon with high efficiency. Experimentally, this fiber-optic biosensor is able to detect AFP concentration in phosphate buffered saline (PBS) solution from 0.1 ng/mL to 100 ng/mL whereas the linear relationship between the AFP concentrations and the fluorescence signals is shown. Furthermore, a linear response between the fluorescence signals and the concentrations of AFP in human serum from 2.33 ng/mL to 143.74 ng/mL is also obtained. As a result, the detection limit of the LSPCF fiber-optic biosensor on AFP detection is comparable with the conventional enzyme-linked immunosorbent assay (ELISA). Additionally, the LSPCF fiber-optic biosensor benefits on inexpensive, disposable and simpler optical geometry that can become a high efficient immunoassay comparable with the conventional ELISA and radioimmunoassay (RIA) clinically.
-
Alpha-fetoprotein Detection by Using a Localized Surface Plasmon Coupled Fluorescence Fiber-Optic Biosensor
Optics in Health Care and Biomedical Optics III, 2007Co-Authors: Ying-feng Chang, Ran-chou Chen, Bao-yu Hsieh, Chien ChouAbstract:Alpha-fetoprotein (AFP) detection by using a Localized Surface Plasmon coupled fluorescence (LSPCF) fiber-optic biosensor is setup and experimentally demonstrated. It is based on gold nanoparticle (GNP) and coupled with Localized Surface Plasmon wave on the Surface of GNP. In this experiment, the fluorophores are labeled on anti-AFP which are bound to protein A conjugated GNP. Thus, LSPCF is excited with high efficiency in the near field of Localized Surface Plasmon wave. Therefore, not only the sensitivity of LSPCF biosensor is enhanced but also the specific selectivity of AFP is improved. Experimentally, the ability of real time measurement in the range of AFP concentration from 0.1ng/ml to 100ng/ml was detected. To compare with conventional methods such as enzyme-linked immunosorbent assay (ELISA) or radioimmunoassay (RIA), the LSPCF fiber-optic biosensor performs higher or comparable detection sensitivity, respectively.
-
Localized Surface Plasmon Coupled Fluorescence Fiber-Optic Biosensor with Gold Nanoparticles
Analytical chemistry, 2007Co-Authors: Bao-yu Hsieh, Wei Chih Liu, Ying-feng Chang, Chao-hsiung Lin, Chien ChouAbstract:A novel fiber-optic biosensor based on a Localized Surface Plasmon coupled fluorescence (LSPCF) system is proposed and developed. This biosensor consists of a biomolecular complex in a sandwich format of . It is immobilized on the Surface of an optical fiber where a complex forms the fluorescence probe and is produced by mixing Cy5-labeled antibody and protein A conjugated gold nanoparticles (Au-PA). The LSPCF is excited by Localized Surface Plasmon on the GNP Surface where the evanescent field is applied near the core Surface of the optical fiber. At the same time, the fluorescence signal is detected by a photomultiplier tube located beside the unclad optical fiber with high collection efficiency. Experimentally, this novel LSPCF biosensor is able to detect mouse immunoglobulin G (IgG) at a minimum concentration of 1 pg/mL (7 fM) during the biomolecular interaction of the IgG with anti-mouse IgG. The analysis is expanded by a discu...
Liang-yan Hsu - One of the best experts on this subject based on the ideXlab platform.
-
Controllable Frequency Dependence of Resonance Energy Transfer Coupled with Localized Surface Plasmon Polaritons.
The journal of physical chemistry letters, 2020Co-Authors: Ming-wei Lee, Liang-yan HsuAbstract:We investigate the intrinsic characteristics of resonance energy transfer (RET) coupled with Localized Surface Plasmon polaritons (LSPPs) from the perspective of macroscopic quantum electrodynamics...
Jing Zhao - One of the best experts on this subject based on the ideXlab platform.
-
resonance Localized Surface Plasmon spectroscopy sensing substrate and inhibitor binding to cytochrome p450
Journal of Physical Chemistry C, 2008Co-Authors: Jing Zhao, Aditi Das, George C Schatz, Stephen G Sligar, Richard P Van DuyneAbstract:A sensing method based on resonance Localized Surface Plasmon spectroscopy was developed for low molecular weight substrate and inhibitor molecules binding to heme proteins. Cytochrome P450 proteins have Soret and Q absorption bands in the visible wavelength region. The coupling between the molecular resonance of P450 and the Localized Surface Plasmon resonance (LSPR) of functionalized silver nanoparticles leads to a highly wavelength-dependent LSPR response. Binding of substrate (e.g., camphor) or inhibitor (e.g., imidazole) molecules to a cytochrome P450 causes the absorption band of cytochrome P450 shift to shorter or longer wavelengths, respectively. By monitoring the Localized Surface Plasmon resonance (LSPR) of the nanosensors, the binding of camphor/imidazole to a nanoparticle whose Surface is modified with cytochrome P450 protein leads to a wavelength-dependent blue/red shift in the LSPR. The magnitude of the LSPR shift induced by camphor or imidazole is consistent with the Soret band wavelength shift observed in P450 in solution.
-
Localized Surface Plasmon resonance biosensors
Nanomedicine: Nanotechnology Biology and Medicine, 2006Co-Authors: Jing Zhao, Amanda J Haes, Xiaoyu Zhang, Chanda Ranjit Yonzon, Richard P Van DuyneAbstract:In this review, the most recent progress in the development of noble metal nano-optical sensors based on Localized Surface Plasmon resonance (LSPR) spectroscopy is summarized. The sensing principle relies on the LSPR spectral shifts caused by the surrounding dielectric environmental change in a binding event. Nanosphere lithography, an inexpensive and simple nanofabrication technique, has been used to fabricate the nanoparticles as the LSPR sensing platforms. As an example of the biosensing applications, the LSPR detection for a biomarker of Alzheimer's disease, amyloid-derived diffusable ligands, in human brain extract and cerebrospinal fluid samples is highlighted. Furthermore, the LSPR sensing method can be modified easily and used in a variety of applications. More specifically, a LSPR chip capable of multiplex sensing, a combined electrochemical and LSPR protocol and a fabrication method of solution-phase nanotriangles are presented here.
-
Localized Surface Plasmon resonance spectroscopy near molecular resonances
Journal of the American Chemical Society, 2006Co-Authors: Amanda J Haes, Jing Zhao, George C Schatz, Shengli Zou, Richard P Van DuyneAbstract:The peak location of the Localized Surface Plasmon resonance (LSPR) of noble metal nanoparticles is highly dependent upon the refractive index of the nanoparticles' surrounding environment. In this study, new phenomena are revealed by exploring the influence of interacting molecular resonances and nanoparticle resonances. The LSPR peak shift and line shape induced by a resonant molecule vary with wavelength. In most instances, the oscillatory dependence of the peak shift on wavelength tracks with the wavelength dependence of the real part of the refractive index, as determined by a Kramers−Kronig transformation of the molecular resonance absorption spectrum. A quantitative assessment of this shift based on discrete dipole approximation calculations shows that the Kramers−Kronig index must be scaled in order to match experiment.
