Search query: surface plasmon induced direct detection

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abstract: Millimeter and terahertz wave photodetectors have long been of great interest due to a wide range of applications, but they still face challenges in detection performance. Here, we propose a new strategy for the direct detection of millimeter and terahertz wave photons based on localized surface plasmon polariton (SPP) induced non equilibrium electrons in antenna assisted subwavelength ohmic metal semiconductor metal (OMSM) structures. The subwavelength OMSM structure is used to convert the absorbed photons into localized SPPs, which then induce non equilibrium electrons in the structure, while the antenna increases the number of photons coupled into the OMSM structure. When the structure is biased and illuminated, the unidirectional flow of the SPP induced non equilibrium electrons forms a photocurrent. The energy of the detected photons is determined by the structure rather than the band gap of the semiconductor. The detection scheme is confirmed by simulation and experimental results from the devices, made of gold and InSb, and a room temperature noise equivalent power (NEP) of 1.5 x 10 13 W Hz 1/2 is achieved.The detection of terahertz and millimeter waves has many applications, but there are still limitations in their technical performance. Here, Tong et al. demonstrate the direct detection of long wavelength radiation through surface plasmon excitation and a corresponding improvement in detection performance.
author_names: Jinchao Tong

Wei Zhou

Yue Qu

Zhengji Xu

Zhiming Huang

Dao Hua Zhang
title: Surface plasmon induced direct detection of long wavelength photons
venue: Nature Communications
year: 2017

abstract: Abstract Over secretion of cortisol from the adrenal cortex is closely related to acute and chronic stress; thus, rapid and sensitive detection of cortisol in serum is of critical importance for preventing the progression of stress related diseases. The binding of a biological molecule to the surface of metallic nanoparticles changes the local refractive index and in turn induces a shift in the localized surface plasmon resonance (LSPR) wavelength. Utilizing this phenomenon, we designed a novel disposable LSPR based cuvette type sensor for detecting cortisol in serum. The developed cuvette type nanosensor consists primarily of an assembly of plastic unit sensors coated with gold nanoparticles on a single layer wherein cortisol conjugated bovine serum albumin (BSA) is immobilized. In this system, a redshift in LSPR wavelength is induced by the binding of cortisol antibody onto cortisol conjugated BSA immobilized on a gold nanoparticle surface in the nanosensor. In a competitive assay, the nanosensor could rapidly detect cortisol in both a PBS solution and serum (within 20 min) at concentrations ranging from 1 to 10,000 ng/mL (2.759 3 x 103 nmol/L) which is comparable to conventional enzyme linked immunosorbent assay (ELISA) which typically requires longer than 4 h and complex sample preparation. Thus, we demonstrated that the LSPR based nanosensor system developed in this study can provide a useful toolkit for a rapid, highly sensitive and reliable detection of cortisol hormone in a commercially available manner.
author_names: Jeong Jin-Woo

Saji Uthaman

Ji-young Lee

Hyejin Hwang

Gibum Kim

Pil J Yoo

Bruce D Hammock

Christina S Kim

Park Yeon-Su

In-Kyu Park
title: In direct localized surface plasmon resonance (LSPR) based nanosensors for highly sensitive and rapid detection of cortisol
year: 2018

abstract: We show femtosecond direct laser induced assembly of gold nanostructures with plasmon resonance band variable as a function of laser irradiation in a wide range of visible wavelengths. A system of 2 photon lithography is used to achieve site selectively controlled dewetting of a thin gold film into nanostructures in which size and shape are highly dependent on the laser power. Simultaneous measurements of localized surface plasmon resonance (LSPR) and surface enhanced Raman scattering (SERS) in the presence of various concentrations of trans 1,2 bis(4 pyridyl) ethylene (BPE) as target molecule are performed in order to highlight the relationship between structural dimensions, plasmonic effect, and detection activity. The resulting gold NPs exhibit high sensitivity as both LSPR and SERS sensors and allow the detection of picomolar concentrations of BPE with a SERS enhancement factor (SEF) of 1.33 x 109 and a linear detection range between 10 3 and 10 12 M.
author_names: Safi Jradi

Lama Zaarour

Zeinab Chehadi

Suzanna Akil

Jerome Plain
title: Femtosecond Direct Laser Induced Assembly of Monolayer of Gold Nanostructures with Tunable Surface Plasmon Resonance and High Performance Localized Surface Plasmon Resonance and Surface Enhanced Raman Scattering Sensing.
venue: Langmuir the ACS journal of surfaces and colloids
year: 2018

abstract: We experimentally demonstrate the uncooled detection of long wavelength infrared (IR) radiation by thermal surface plasmon sensing using an all optical readout format. Thermal infrared radiation absorbed by an IR sensitive material with high thermo optic coefficient coated on a metal grating creates a refractive index change detectable by the shift of the supported surface plasmon resonance (SPR) measured optically in the visible spectrum. The interface localization of SPR modes and optical readout allow for submicrometer thin film transducers and eliminate complex readout integrated circuits, respectively, reducing form factor, leveraging robust visible detectors, and enabling low cost imaging cameras. We experimentally present the radiative heat induced thermo optic action detectable by SPR shift through imaging of a thermal source onto a bulk metal grating substrate with IR absorptive silicon nitride coating. Toward focal plane array integration, a route to facile fabrication of pixelated metal grating structures by nanoimprint lithography is developed, where a stable polymer, parylene C, serves as an IR absorptive layer with a high thermo optic coefficient. Experimental detection of IR radiation from real thermal sources imaged at infinity is demonstrated by our nanoimprinted polymer SPR pixels with an estimated noise equivalent temperature difference of 21.9 K.
author_names: Brandon Hong

Felipe Vallini

Cheng-Yi Fang

Amr Alasaad

Yeshaiahu Fainman
title: Simple Nanoimprinted Polymer Nanostructures for Uncooled Thermal Detection by Direct Surface Plasmon Resonance Imaging.
venue: ACS applied materials interfaces
year: 2017

abstract: Abstract For the first time, plasmonic diffraction grating is implemented for the combined direct and epifluorescence based readout of assays in real time. This plasmonic structure serves for grating coupled surface plasmon resonance (SPR) monitoring of molecular binding induced changes in the refractive index. In parallel, it allows to simultaneously perform plasmonically enhanced fluorescence (PEF) analysis of affinity binding of molecules that are labeled with fluorophores. This configuration offers facile readout of e.g. magnetic nanoparticle enhanced assays which is not possible with more conventional Kretschmann geometry. The performance characteristics of this combined approach are discussed by using two types of assays. In the first assay a fluorophore labeled protein with a medium molecular weight of 55 kDa was affinity captured on the plasmonic sensor grating. The associated PEF signal in this assay showed a signal to noise ratio that was 140 fold higher compared to that of the SPR detection channel. In the second assay, extracellular vesicles were detected by using antibodies against CD81 attached to the plasmonic grating. These vesicles were pre concentrated by their coupling to magnetic nanoparticles with cholera toxin B chain. This assay exploited magnetic nanoparticles as labels enabling rapid collection of analyte at the sensor surface and for the enhancement of the SPR sensor response. In this case the label free SPR detection channel outperformed the fluorescence based detection, as the SPR signal to noise ratio was 2.4 fold higher than that of PEF.
author_names: Agnes T Reiner

Stefan Fossati

Jakub Dostalek
title: Biosensor platform for parallel surface plasmon enhanced epifluorescence and surface plasmon resonance detection
year: 2018

abstract: Conventional analysis of molecular interactions by surface plasmon resonance is achieved by the observation of optical density changes due to analyte binding to the ligand on the surface. Low molecular weight interaction partners are normally not detected. However, if a macromolecule such as DNA can extend beyond the evanescent field and analyte interaction results in a large scale contraction, then the refractive index changes due to the increasing amount of macromolecules close to the surface. In our proof of principle experiment we could observe the direct folding of long, human telomeric repeats induced by the small analyte potassium using surface plasmon resonance spectroscopy. This work demonstrates the feasibility of new evanescent field based biosensors that can specifically observe small molecule interactions.
author_names: Constanze Schlachter

Fred Lisdat

Marcus Frohme

Volker A Erdmann

Zoltan Konthur

Hans Lehrach

Jorn Glokler
title: Pushing the detection limits: the evanescent field in surface plasmon resonance and analyte induced folding observation of long human telomeric repeats.
venue: Biosensors bioelectronics
year: 2012

abstract: Small molecules or analytes present in trace level are difficult to be detected directly using conventional surface plasmon resonance (SPR) sensor, due to its small changes in the refractive index induced by the binding of these analytes on the sensor surface. In this paper, a new approach that combines SPR sensor technology with Fe3O4 magnetic nanoparticles (MNPs) assays is developed for directly detecting of deltamethrin in soybean. The Fe3O4 MNPs conjugated with antibodies specific to antigen serves as both labels for enhancing refractive index change due to the capture of target analyte, and "vehicles" for the rapid delivery of analyte from a sample solution to the sensor surface. Meanwhile, SPR direct detection format without Fe3O4 MNPs and gas chromatography (GC) analysis were conducted for detection of deltamethrin in soybean to demonstrate the amplification effect of Fe3O4 MNPs. A good linear relationship was obtained between SPR responses and deltamethrin concentrations over a range of 0.01 1 ng/mL with the lowest measurable concentration of 0.01 ng/mL. The results reveal that the detection sensitivity for deltamethrin was improved by 4 orders of magnitude compared with SPR direct detection format. The recovery of 95.5 119.8% was obtained in soybean. The excellent selectivity of the present biosensor is also confirmed by two kinds of pesticides (fenvalerate and atrazine) as controls. This magnetic separation and amplification strategy has great potential for detection of other small analytes in trace level concentration, with high selectivity and sensitivity by altering the target analyte capture agent labeled to the carboxyl coated Fe3O4 MNPs.
author_names: Xia Liu

Lei Li

Youqian Liu

Xingbo Shi

Wen-Jin Li

Yang Yang

Lu-Gang Mao
title: Ultrasensitive detection of deltamethrin by immune magnetic nanoparticles separation coupled with surface plasmon resonance sensor.
venue: Biosensors bioelectronics
year: 2014

abstract: It's difficult to detect single nanoparticle and virus because their sizes are too tine, which is below 100nm. However, nano pollutants and virus in the water and atmospheric environment have a serious impact on human life. We present a method to detect the single nanoparticle and virus by direct imaging the surface plamon scattering induced by nanoparticle or virus. The schematic is shown in Figure 1. Experimentally, single 39nm polystyrene particle has been "seen" (as shown in Figure 2) and three viruses, e.g. T4 phage, PR8 influenza virus and EV71 enterovirus, have been detected in PBS buffer solution. This method is fast, high sensitivity, simple and low cost, which has a potential application to in situ monitor the water and atmospheric environment.
author_names: Xinchao Lu

Hongyao Liu

Xuqing Sun

Yaqin Chen

Wei Xiong
title: Fast detection to single nanoparticle and virus by using surface Plasmon scattering imaging
year: 2016

abstract: Light manipulation is vitally important for one dimensional semiconductor nanostructure based photodetectors which have great potential in future optoelectronic circuits, imaging technique, and light wave communication. In this paper, we reported a plasmonic gold nanoparticle (AuNP) decorated nano photodetector for green light sensing. It is found that the as fabricated device exhibits obvious increase in light absorption in the range from 400 to 550 nm, after functionalization of plasmonic AuNPs. Further device performance analysis reveals that the photocurrent of the plasmonic photodetector was increased by more than sevenfold, compared with that without coating. What is more, both responsivity and detectivity are found to increase as well. According to theoretical simulation based on the finite element method (FEM) the observed enhancement in device performance can be attributed to the surface plasmon induced direct electron injection from the metal nanoparticles to the semiconductor nanostructures.
author_names: Lin-Bao Luo

Kun Zheng

Caiwang Ge

Yi-Feng Zou

Rui Lu

Yuan Wang

Dan-dan Wang

Tengfei Zhang

Feng-xia Liang
title: Surface Plasmon Enhanced Nano photodetector for Green Light Detection
venue: Plasmonics
year: 2015

abstract: Cytotoxic T lymphocytes (CTL) recognize antigens as peptides associated with molecules of the major histocompatibility complex (MHC) The accurate characterization of antigenic peptides requires knowledge of how peptides bind to MHC molecules, and hence the conformational changes they can induce. Several reports have indicated that the conformation of the MHC class I molecule plays a role in T cell recognition. We therefore studied the interaction of a series of viral epitopes with HLA A2, A3, B7 and B8 molecules to determine how peptides could induce conformational changes in HLA molecules. This was done either directly with class I heavy chains in lysates of peptide loading deficient T2 cells, or with purified material from B EBV transformed cell lines. The peptide induced HLA conformations were assessed using monoclonal anti HLA antibodies (mAbs) and detected by surface plasmon resonance (SPR) Antigenic peptides specifically bound to the HLA molecule, even when assembly occurred in a mixed solution of HLA molecules. Distinct patterns of reactivity to a given peptide bound class I molecule were obtained with monomorphic and allele specific anti HLA mAbs.
author_names: F Hlavac

Francine Connan

Johan Hoebeke

Jean Gerard Guillet

Jeannine Choppin
title: Direct detection of peptide dependent HLA variability by surface plasmon resonance.
venue: Molecular immunology
year: 1996