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Anti-Stokes Emission from Hot Carriers in Gold Nanorods
摘要： The origin of light emission from plasmonic nanoparticles has been strongly debated lately. It is present as the background of surface enhanced Raman scattering, and, despite the low yield, has been used for novel sensing and imaging application because of its photostability. While the role of surface plasmons as an enhancing antenna is widely accepted, the main controversy regarding the mechanism of the emission is its assignment to either radiative recombination of hot carriers (photoluminescence) or electronic Raman scattering (inelastic light scattering). We have previously interpreted the Stokes shifted emission from gold nanorods as the Purcell effect enhanced radiative recombination of hot carriers. Here we specifically focused on the anti-Stokes emission from single gold nanorods of varying aspect ratios with excitation wavelengths below and above the inter-band transitions threshold while still employing continuous wave lasers. Analysis of the intensity ratios between Stokes and anti-Stokes emission yields temperatures that can only be interpreted as originating from the excited electron distribution and not a thermally equilibrated phonon population despite not using pulsed laser excitation. Consistent with this result as well as previous emission studies using ultrafast lasers, the power-dependence of the upconverted emission is nonlinear and gives the average number of participating photons as a function of emission wavelength. Our findings thus show that hot carriers and photoluminescence play a major role in the upconverted emission.
关键词： surface plasmon resonance,anti-Stokes photoluminescence,interband transition,intraband transition,hot electron temperature,gold nanoparticle
更新于2025-09-19 17:15:36
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Localized surface plasmon resonance scattering imaging and spectroscopy for real-time reaction monitoring
摘要： In the last decade, plasmonic nanoparticles-based scattering imaging and spectroscopy has introduced the analysis and sensing to the single nanoparticle and molecule level, such as the biomolecules adsorption process and the quantitative detection of small molecules and ions. Recently, this technology has also been focus on the real-time and in-situ reaction monitoring, which is a new emerging branch of the single-nanoparticle imaging, revealing the reaction dynamic information and the related controlling factors. In this mini-review, recent applications of plasmon resonance scattering imaging and spectroscopy in the real-time reaction monitoring in the past 5 years are highlighted and discussed.
关键词： single nanoparticle level,Localized surface plasmon resonance,plasmonic nanoparticles,scattering imaging,reaction monitoring
更新于2025-09-19 17:15:36
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[BestMasters] Topographic Organization of the Pectine Neuropils in Scorpions (An Analysis of Chemosensory Afferents and the Projection Pattern in the Central Nervous System) || Organised Colloidal Metal Nanoparticles for LSPR Refractive Index Transducers
摘要： This work is focused on optimizing adhesion and distribution of colloidal gold nanoparticles on silanized glass substrates intended as nanostructured plasmonic transducer for sensing applications. This system will be used as platform for subsequent functionalization and/or enzyme immobilization. All preparation steps have been monitored by UV-Vis absorption spectroscopy and X-ray photoelectron spectroscopy (XPS).
关键词： Surface plasmon resonance,Silanized substrate,Gold nanoparticles
更新于2025-09-19 17:15:36
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[IEEE 2018 Asia Communications and Photonics Conference (ACP) - Hangzhou, China (2018.10.26-2018.10.29)] 2018 Asia Communications and Photonics Conference (ACP) - A Promising SPR Sensor with Single mode- Multimode-Single mode Fiber Embedding Microcavity
摘要： A cascaded fiber device is proposed basing on a cascaded structure. The device is designed with single mode-multimode-single mode fiber, with a microcavity in the central position of MMF. To get higher energy on the surface of the device, the structure is optimized, which means a strong SPR signal would be excited and a low detection limit would be get. Further, the transmission modes in cavity wall are analyzed, the fundamental modes are found to be the dominant modes.
关键词： Surface Plasmon Resonance,microcavity,Fiber optic sensing,cascade structure
更新于2025-09-19 17:15:36
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[IEEE NAECON 2018 - IEEE National Aerospace and Electronics Conference - Dayton, OH (2018.7.23-2018.7.26)] NAECON 2018 - IEEE National Aerospace and Electronics Conference - Double-Pointed Optical Antenna in the Longwave Infrared (LWIR) Spectral Regime
摘要： Photonic antennas provide an effective approach for the light receiving with engineerable near fields and receiving gains. Various antennas such as dipole, bow-tie, circular disk, circular ring, and pointed-dipole antenna have been reported with an enhancement to infrared detection. In this paper, we report a new double-pointed optical antenna and its enhancement in the longwave infrared (LWIR, 8-12 μm or 25 tera-Hz to 37.5 tera-Hz) spectral regime. The double-pointed photonic antennas are simulated and compared with the single-pointed dipole antenna. It is found that the double-pointed photonic antennas show higher E-fields in the LWIR spectral regime for both the single antenna or coupled antenna configurations. The uncoupled double-pointed dipole antenna can be modeled as an RLC circuit, whereas the coupled double-pointed dipole antennas show clear Fano-type interference between the transmission and the discrete plasmonic resonant modes. The E-fields of the double-pointed antenna are also compared to those of the bow-tie antenna with the same gap dimension.
关键词： Fano-type interference,double-pointed dipole antenna,pointed dipole antenna,surface plasmon resonance,Optical antenna,longwave infrared enhancement
更新于2025-09-19 17:15:36
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Ag-Functionalized CuWO <sub/>4</sub> /WO <sub/>3</sub> nanocomposites for solar water splitting
摘要： Ag-Functionalized CuWO4/WO3 heterostructures were successfully prepared via a polyvinyl pyrrolidone (PVP)-assisted sol–gel (PSG) route. Thin films prepared via electrophoretic deposition were used as photoanodes for photoelectrochemical (PEC) water splitting. Compared to pristine CuWO4 and WO3 films, a significant enhancement of the photocurrent (3–4 times) at the thermodynamic potential for oxygen evolution (0.62 V vs. Ag/AgCl, pH 7) was obtained for the Ag-functionalized CuWO4/WO3 photoanodes. The obtained enhancement is shown to be derived from a synergic contribution of heterostructure formation (CuWO4/WO3) and improvements of light utilization by Ag-induced surface plasmon resonance (SPR) effects. Accordingly, a photocurrent of 0.205 mA cm?2 at 0.62 V vs. Ag/AgCl under neutral conditions (without hole scavengers) under front-side simulated AM1.5G illumination was achieved. A detailed analysis of the obtained PEC data alongside performed impedance measurements suggests that charge separation is significantly improved for the prepared Ag-functionalized CuWO4/WO3 photoanodes. Our work offers beneficial insights to design new plasmonic metal/heterostructured nanocomposites for energy conversion applications.
关键词： nanocomposites,surface plasmon resonance,photoelectrochemical,CuWO4/WO3,solar water splitting,Ag-functionalized,heterostructures
更新于2025-09-19 17:15:36
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A single light spot GC detector employing localized surface plasmon resonance of porous Au@SiO <sub/>2</sub> nanoparticle multilayer
摘要： This paper describes the synthesis of a nano-porous multilayered film consisting of Au@SiO2 nanoparticles. This film was used to miniaturize the size of a localized surface plasmon resonance (LSPR)-based capillary gas chromatograph (GC) detector. A layer-by-layer (LbL) approach with proper surface reaction sequences was used to create a multilayer structure that consisted of as many as five layers of Au@SiO2 nanoparticles. The center wavelength of LSPR was shifted from 520 to 634 nm due to the approximation of additional layers of nanoparticles. The vapor response time for this Au@SiO2 multilayer LSPR sensor was identical to that of an Au nanoparticle monolayer, which confirmed that this multilayer structure has a high level of gas permeability. The multilayer was synthesized inside a glass capillary for use as a GC detector. Due to the enhancement of absorbance, the gas chromatographic signal was obtained via a single spotlight that penetrated one side of the glass capillary and was then reflected by a silver mirror coated on the opposite side. The detection limits were ≤20 ng for cyclohexanone and m-xylene.
关键词： gas chromatography,localized surface plasmon resonance,multilayer film,miniaturization,Au@SiO2 nanoparticles,VOC detection
更新于2025-09-19 17:15:36
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Fe3O4@PDA immune probe-based signal amplification in surface plasmon resonance (SPR) biosensing of human cardiac troponin I
摘要： This work reports immunomagnetic separation technology-assisted surface plasmon resonance (SPR) biosensing for human cardiac troponin-I (cTnI), a well-known diagnostic marker for myocardial damage. Au film modified by Au nanoparticles (AuNPs) and polydopamine (PDA) was employed as the platforms for immobilizing capture antibody (cAb) and SPR sensing. Magnetic immune probe was prepared by attaching detection antibody (dAb) on the surface of Fe3O4 nanoparticles (Fe3O4 NPs) coated by PDA for precise capture, magnetic separation and enrichment of target analyte (cTnI) from samples. This extraction process greatly improves the sensitivity and effectively reduces the nonspecific interference from complex matrixes. The analyte cTnI collected via Fe3O4@PDA-dAb immune probe can be specially recognized by cAb immobilized on the sensing platform. By introducing secondary antibody (Ab2) conjugated with multi-walled carbon nanotube-PDA-AgNPs (MWCNTs-PDA-AgNPs/Ab2) to the sensing system, the residual binding sites of cTnI were occupied, and the SPR response signals were further amplified. The obtained detection limit for cTnI is 3.75 ng mL-1, which is 320-folds lower than that achieved by PDA-based sensing strategy. The present method was applied to the examination of serum samples spiked with cTnI, and the good recoveries demonstrate its future applicability in clinical diagnosis.
关键词： Polydopamine,Human cardiac troponin-I (cTnI),Immune probe,Surface plasmon resonance (SPR),Magnetic separation
更新于2025-09-19 17:15:36
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Spectral Interrogation based SPR Sensor for Blood Glucose Detection with Improved Sensitivity and Stability
摘要： A sensor chip for specific detection of blood glucose was developed. The sensor utilized a surface-plasmon-resonance (SPR) setup on a prism based Kretschmann configuration utilizing spectral interrogation scheme. Self-assembled monolayers (SAMs) based preparation provided the chip stability due to covalent bonds and hence it can be reused for multiple times. Such a scheme can be advantageous in continuous monitoring of blood glucose, without changing the chip. Control experiments were performed without molecular recognition layer to confirm the performance of the sensor. Furthermore, the measurements were performed on blood serums and compared with that of a conventional glucometer. The present sensor has the advantages of improved sensitivity (0.14 nm/(mg/dl)) and stable response for 3 months, which are better compared to existing reports.
关键词： Blood glucose,Self assembled monolayers,Surface plasmon resonance,Biosensor
更新于2025-09-19 17:15:36
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Rectifying Behaviour and Photocatalytic Activity in ZnO Nanorods Array/Ag/CuSe Heterostructure
摘要： Ag incorporated vertically aligned ZnO nanorods array/CuSe thin film (ZnO NRs/CuSe TF) have been fabricated via a solution route, thermal evaporation and magnetron sputtering process. Ternary ZnO nanorods/Ag/CuSe heterostructure was studied by X-ray diffractometry, field emission-scanning electron microscopy/energy dispersive X ray spectroscopy, current–voltage measurement and a UV–Vis–near IR spectrophotometer. The photocatalytic performance was estimated by the degradation of Rhodamine B solution under UV–Vis light irradiation. The photocatalytic efficiency of the ZnO NRs/Ag/CuSe heterostructure is higher than that of ZnO NRs/Ag and ZnO NRs/CuSe counterparts due to the robust effects of the three functional components coupling. The localized surface plasmon resonance and two Schottky junctions (e.g. Ag/ZnO and Ag/CuSe) motivates photogenerated electron–hole separation and transfer. This work presents an artificial manipulated system to enhance light harvesting, efficient charge separation and transfer, and low recombination rate in solar energy conversion.
关键词： Photocatalytic activity,Localized surface plasmon resonance (LSPR),Charge separation,ZnO nanorods array/Ag/CuSe heterostructure
更新于2025-09-19 17:15:36