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- 实验方案
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Waveguide-Coupled Surface Plasmon Resonance Sensor for Both Liquid and Gas Detections
摘要： In this paper, we propose a novel surface plasmon resonance sensor for both liquid and gas detections, which is based on the two dielectric planar waveguide (PWG)-coupled plasmonic structure. Two sharp Fano-type resonances, which arise from the electromagnetic coupling between surface plasmon polariton (SPP) and PWG modes, appear in the reflection curve, and they can be used to monitor the minute changes of the refractive indices of gas and liquid due to their high imaging sensitivities (> 9.0 × 103 RIU?1). The Fano resonance angles and the figures of merit for imaging sensitivity can be effectively manipulated by the thicknesses of guiding layers, and the sensor system can measure over a wide range of the refractive indices of sensing media.
关键词： Electromagnetic coupling,Planar waveguide mode,Fano resonance,Surface plasmon resonance
更新于2025-09-19 17:13:59
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Plasmonic Nanoparticle Film for Low-Power NIR-Enhanced Photocatalytic Reaction
摘要： Plasmonic metal nanostructures offer the unique ability to effectively enhance sunlight harvesting by localized surface plasmon resonance (LSPR), which can induce direct photocatalytic reactions. However, only metal nanoparticles with a relatively low magnitude of electromagnetic field enhancement usually require a high illumination intensity to ensure the catalytic performance, which greatly limits the solar photocatalytic efficiency. Herein, we designed plasmonic Au nanoparticle film with high electromagnetic field enhancement to achieve high-efficiency catalytic activity under low power NIR light illumination. This work minimized the influence of the photothermal effect on the reaction by using a low illumination intensity and further revealed the main contribution of plasmon-excited hot electrons to the photochemical reaction. This study provides important insights into the study of the mechanism of LSPR in photocatalytic reactions and further improves the efficiency of solar energy utilization.
关键词： Localized surface plasmon resonance,hot electrons,low power illumination,electromagnetic field enhancement,NIR photocatalysis
更新于2025-09-19 17:13:59
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Lab-on-tip: Protruding-shaped all-fiber plasmonic microtip probe toward in-situ chem-bio detection
摘要： Lab-on-tip technology opens a new door for optical fiber surface plasmon resonance (SPR) sensors. In this paper, we first demonstrate an ultra-compact reflective SPR microtip probe on the flat fiber end in experiment, which has a length of tens of microns and a diameter of several microns. Simulations and experiments show that this new fiber SPR microtip probe coated with a nano-goldfilm has excellent refractive index (RI) sensing characteristic and great potential for biochemical detection at single cell level. Based on the high RI sensitivity, a bio-probe assembled with Chitosan/Polysodium Styrene Sulfonate (Cs/PSS) nano-polyelectrolyte film and the sheep anti-human IgG-HRP is prepared to recognize human IgG specifically. Due to the high surface sensitivity, the SPR microtip probe exhibits an ultra-low detection limit for human IgG. Due to the high bulk sensitivity and high thermo-optical coefficient (TOC) of polydimethylsiloxane (PDMS), a reference temperature probe based on SPR microtip is proposed, which is used to compensate for the temperature cross-sensitivity of the bio-probe. This new SPR microtip probe can be used not only in optical fiber sensor, but also in Tip-Enhanced Near-Field Raman Microscopy and Scanning Near-Field Optical Microscope.
关键词： Surface plasmon resonance,Optical fiber microtip,Refractive index detection,Antibody detection
更新于2025-09-19 17:13:59
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Enhanced Visible-light-driven Photoelectrochemical and Photocatalytic Performance of Au-SnO2 quantum dot-anchored g-C3N4 Nanosheets
摘要： A novel g-C3N4/Au-SnO2 quantum dot (g-CN/Au-SQD) ternary nanocomposite was fabricated via a three-step approach for the degradation of the organic pollutant rhodamine B (RhB), and photoelectrochemical (PEC) water splitting upon visible light illumination. Au-SQDs were prepared via a one-pot chemical reduction method, and g-CN was synthesized via the thermal polymerization of urea at 550 ℃. The g-CN/Au-SQD ternary nanocomposite was prepared via sonication, stirring, and finally annealing. This approach was effective for the mixing and dispersion of Au-SQDs over the entire surface of the two-dimensional (2D) g-CN nanosheets. Morphological studies revealed that the Au-SQDs were well-distributed over the nanolayers of the g-CN. The light-capturing ability was improved and optimized with the loading of different amounts of Au-SQDs. The bandgap was tuned from 2.85 eV (g-CN) to 2.58 eV (g-CN/Au-SQD). Photoluminescence analysis revealed the inhibited nature of recombination of electrons and holes in the ternary nanocomposites. Optimization yielded CNAS-20, which exhibited the best photocatalytic performance within 40 min for the degradation of the pollutant RhB. Furthermore, the CNAS-20 photoelectrode showed lower charge-transfer resistance than the other prepared samples, which was favorable for PEC water splitting. The CNAS-20 photoelectrode exhibited a significant photocurrent, which was ~3.83 times greater than that of pure g-CN. Thus, this unique design incorporates a 2D g-CN and plasmonic Au metal nanoparticles for the generation of photoexcited electrons, and SQDs receive these photogenerated electrons to increase the leave-taking of electron and holes to enhance the photocatalytic and PEC activities.
关键词： Quantum dots,Photocatalysis,g-C3N4,Au-SnO2,Surface plasmon resonance
更新于2025-09-19 17:13:59
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Laser-Induced Optoacoustic Spectroscopy Studies of Inorganic Functionalized Metallic Nanorods
摘要： Plasmonic nanoparticles can be used in photothermal therapy thanks to their ability to generate local heat. The light-to-heat conversion efficiency is crucial for therapeutic and diagnostic applications. The photothermal properties of gold nanorods functionalized with silica layers of controllable thickness were characterized using both theoretical and experimental approaches. The time-resolved laser-induced optoacoustic spectroscopy (LIOAS) was used to determine the amount of absorbed energy changed promptly into heat. The heat generation efficiencies were simulated by the means of finite integration technique. The obtained parameters were correlated with silica thickness. Experimental results are consistent with theoretical predictions, thus LIOAS is a unique reliable method for studying photothermal effect in gold nanoparticles.
关键词： noble metal nanoparticles,finite integration technique,laser-induced optoacoustic spectroscopy,surface plasmon resonance,photothermal effect
更新于2025-09-19 17:13:59
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Thermal annealing induced cave in and formation of nanoscale pits in Ag–TiO2 plasmonic nanocomposite thin film
摘要： Ag–TiO2 nanocomposite thin films on silica glass were prepared through thermal evaporation in combination with RF magnetron sputtering. Thermal annealing induced changes in the optical, morphological and structural properties of Ag–TiO2 nanocomposites were examined using optical absorption, photoluminescence spectroscopy, Raman spectroscopy, FESEM, AFM and XRD. FESEM and AFM studies revealed cave in of the Ag–TiO2 thin film at various places leading to the formation nanoscale pits upon thermal annealing at 600 °C. The computed average size of pits was found to be 54 nm. Raman studies indicated 600 °C annealing induced transformation of anatase phase of TiO2 into anatase/rutile mixed phase TiO2. Optical absorption spectra showed systematic changes due to the effects of mixed phase formation and variation in the plasmonic behavior upon annealing. PL results of the as deposited Ag–TiO2 thin film showed peaks at 377, 402, 432 and 486 nm. PL studies of Ag–TiO2 nanocomposites treated at different annealing temperatures revealed changes in defect concentration in TiO2. The tentative mechanism for the creation of nanoscale pits in Ag–TiO2 thin film through thermal annealing was proposed.
关键词： Nanocomposite,Surface plasmon resonance,TiO2,Ag,Photoluminescence
更新于2025-09-19 17:13:59
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Development of an optoelectronic nose based on surface plasmon resonance imaging with peptide and hairpin DNA for sensing volatile organic compounds
摘要： Nowadays, the analysis of volatile organic compounds (VOCs) is very important in various domains. In the last decades, electronic noses have emerged as promising alternatives to traditional analytical methods. Nevertheless, their wide use is still limited by their performances such as low selectivity. Herein, we developed an optoelectronic nose using virtually screened peptides and hairpin DNA (hpDNA) with improved selectivity as sensing materials and surface plasmon resonance imaging (SPRi) as the detection system. Thanks to the complementarity of their binding properties towards target VOCs, the obtained optoelectronic nose has very good selectivity, being able to discriminate not only between VOCs of different chemical families, but also VOCs of the same family with only 1-carbon difference. The combination of these sensing materials with SPRi is relevant for the development of optoelectronic nose with large sensor arrays and improved performances.
关键词： Volatile organic compounds,Surface plasmon resonance imaging,E-nose,Peptides,Optoelectronic nose,Hairpin DNA
更新于2025-09-19 17:13:59
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Plasmonic gold nanorods mediated p-BFCrO/n-rGO heterojunction in realizing efficient ferroelectric photovoltaic devices
摘要： In this work, we introduce a chemically synthesised lead-free ferroelectric thin film 2% Cr doped BiFeO3 (BFCrO) for possible photovoltaic (PV) applications. The first set of PV devices were fabricated onto ITO/glass electrode by utilizing BFCrO as an active material and Pt as top electrode. The obtained ferroelectric and electrical results were systematically compared with the conventional BFO and the BFCrO device was found to be a potential one. To further enhance the PV performance, highly conducting n-type reduced graphene oxide (rGO) was heterogeneously employed as an electron transport layer (ETL) in between ITO and BFCrO. Surprisingly, the JSC was significantly improved by 1000 times along with amended VOC and FF as compared to the standalone BFCrO device. Furthermore, an attempt has been made to embed plasmonic Au nanorods (NRs) in between rGO and BFCrO, which alleviates the absorbance in heterojunction through localized surface plasmonic effect, ultimately offered remarkable PV performances than conventional BFO one. The Au NRs based BFCrO/rGO PV device exhibited an increased VOC and JSC of 0.63 V and 2.56 mA/cm2, respectively as compared to the BFCrO/rGO device with VOC (0.56 V) and JSC (1.54 mA/cm2). Effort was devoted to establish ferroelectricity in BFCrO and the effect of positive and negative polarizations on J-V measurements were observed in with or without Au NRs based devices. The modulation in charge transport with polarization field and improved photoresponse were explained by projecting a band diagram, which also provides a comprehensive understanding on the operation principle of the fabricated devices.
关键词： Ferroelectric polarization,Heterointerface,Photovoltaic effect,Electron transport layer,Plasmon resonance
更新于2025-09-19 17:13:59
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Tunable plasmonic properties of graphene ribbon for hypersensitive nanosensing
摘要： Plasmonic sensing based on symmetrical and asymmetrical graphene metamaterials at the infrared region are proposed and investigated numerically by using three dimensional finite-difference time-domain (FDTD) method. The simple unit cell structure is composed of two parallel graphene ribbons and strips. It is shown that transmission resonance dip shifts can be achieved with a variation of the chemical potential of the graphene ribbon.The sensitivity of the proposed metamaterial is also calculated. Our simulations reveal that, by modulating the chemical potential from 0.8 eV to 0.5 eV, a single layer asymmetrical graphene ribbon can achieve a sensitivity of 6500 nm/RIU, compared to 5725 nm/RIU for double layer asymmetrical graphene ribbons. The finding will pave the way towards graphene based tunable devices for sensing in infrared region.
关键词： Surface plasmon resonance,Metamaterial,Graphene,Optical transmission
更新于2025-09-19 17:13:59
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Plasmonics of Au/Polymer Core/Shell Nanocomposites for Thermoresponsive Hybrid Metasurfaces
摘要： We investigate the temperature-dependent optical response of ordered lattices of non-interacting gold-core/poly(N-isopropylacrylamide)-shell nanoparticles (NPs), a system with proven photothermal and sensing capabilities. For the first time on this system, we exploited in situ Spectroscopic Ellipsometry (SE) to determine the complex, temperature-dependent optical properties of the lattice, a key piece of information which, however, is often overlooked. In doing so, we take full advantage of large-scale colloidal self-assembly, which makes NP lattices accessible to conventional SE. A quantitative interpretation of the SE data is obtained through an effective model based on the actual characteristics of the NPs and their dielectric environment. The model allows to estimate temperature-dependent morphological parameters, such as the distance between the gold cores and the substrate, also yielding the complex permittivity of the plasmonic NP lattice. Thus, by combining the high sensitivity of SE with proper modelling, we provide a comprehensive characterization of thermoresponsive NP lattices. The approach proposed here is instrumental to the analysis and design of functional hybrid metasurfaces with plasmonic functionalities, including particle-to-film coupled systems.
关键词： spectroscopic ellipsometry,PNIPAM,localized surface plasmon resonance,complex permittivity,core-shell particles
更新于2025-09-19 17:13:59