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- 实验方案
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Surface Plasmon Resonance Effect Enhanced CsPbBr <sub/>3</sub> Inverse Opals for Higha??Performance Inorganic Perovskite Solar Cells
摘要： Although all-inorganic CsPbBr3 are considered an ideal candidate for inorganic perovskite solar cells (PSCs) owing to their outstanding thermal- and moisture-resistance, it still suffers from unfavorable charge transfer process and limited light harvesting ability. Herein, CsPbBr3 inverse opal (IO) films coupled with Au nanoparticles (NPs) are rationally designed, and PSCs based on Au-CsPbBr3 IO achieve a stabilized photoelectric conversion efficiency up to 8.08%. By selectively tuning IO pore diameter, the slow photon region of CsPbBr3 IO and localized surface plasmon resonance (SPR) region from Au NPs can be modulated to be overlapped to enhance the performance of inorganic CsPbBr3 PSCs. The synergetic effect devotes to light utilization and charge transfer process, resulting in an enhanced light absorption capability and suppressed recombination rate of photogenerated electron–hole pairs. The introduction of Au not only triggers SPR effect, but also enhances efficient separation/injection of charge carriers owing to the Schottky barriers. Furthermore, it is revealed that simultaneous effect from SPR and IO photon effect are conducive to reduce exciton binding energy, enhancing exciton dissociation efficiency and leading to significant increase in free carrier density. This work provides a rational strategy for plasmonic metal/semiconductor composite light-absorber for high-performance inorganic PSCs.
关键词： inverse opal,inorganic perovskites,Au nanoparticles,surface plasmon resonance,slow photon effects
更新于2025-09-23 15:21:01
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Effect of Surface Plasmon Resonance on the Anomalous Result of Young’s Double-Slit Experiment with a Metal Screen
摘要： An abnormal result of Young’s classic experiment with two slits in a metal screen is discussed, in which the appearance of a light spot behind a screen located centrally between the images of the slits is unusual. It is shown that the anomaly is caused by plasmon resonance in the metal–dielectric structure. The intensity of the diffraction pattern is calculated. Under resonance conditions, it overcomes the diffraction limit.
关键词： Young’s double-slit experiment,metal screen,diffraction limit,plasmon resonance
更新于2025-09-23 15:21:01
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Self-Referencing Plasmonic Array Sensors
摘要： A self-referencing plasmonic platform is proposed and analyzed. By introducing a thin gold layer below a periodic two-dimensional nano-grating, the structure supports multiple modes including localized surface plasmon resonance (LSPR), surface plasmon resonance (SPR), and Fabry-Perot resonances. These modes get coupled to each other creating multiple Fano resonances. A coupled mode between the LSPR and SPR responses is spatially separated from the sensor surface and is not sensitive to refractive index changes in the surrounding materials or surface attachments. This mode can be used for self-referencing the measurements. In contrast, the LSPR dominant mode shifts in wavelength when the refractive index of the surrounding medium is changed. The proposed structure is easy to fabricate using conventional lithography and electron beam deposition methods. A bulk sensitivity of 429 nm/RIU is achieved. The sensor also has the ability to detect nanometer thick surface attachments on the top of the grating.
关键词： Surface plasmon resonance,Self-referencing,Nano-grating
更新于2025-09-23 15:21:01
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Selective Uropathogenic E. coli Detection Using Crossed Surface-Relief Gratings
摘要： Urinary tract infections (UTIs) are one of the major burdens on public healthcare worldwide. One of the primary causes of UTIs is the invasion of the urinary tract by uropathogenic Escherichia coli (UPEC). Improper treatment of bacterial infections like UTIs with broad-spectrum antibiotics has contributed to the rise of antimicrobial resistance, necessitating the development of an inexpensive, rapid and accurate detection of UPEC. Here, we present real-time, selective and label-free detection of UPEC using crossed surface-relief gratings (CSRGs) as nanometallic sensors incorporated into an optical sensing platform. CSRGs enable real-time sensing due to their unique surface plasmon resonance (SPR)-based light energy exchange, resulting in detection of a very-narrow-bandwidth SPR signal after the elimination of residual incident light. The platform’s sensing ability is experimentally demonstrated by the detection of bulk refractive index (RI) changes, with a bulk sensitivity of 382.2 nm/RIU and a resolution in the order of 10?6 RIU. We also demonstrate, for the ?rst time, CSRG-based real-time selective capture and detection of UPEC in phosphate-buffered saline (PBS) solution, in clinically relevant concentrations, as opposed to other UTI-causing Gram-negative bacteria. The platform’s detection limit is calculated to be 105 CFU/mL (concentration on par with the clinical threshold for UTI diagnosis), with a dynamic range spanning four orders of magnitude. This work paves the way for the development of inexpensive point-of-care diagnosis devices focusing on effective treatment of UTIs, which are a burden on public healthcare due to the rise in the number of cases and their recurrences in the recent past.
关键词： crossed surface-relief gratings,nanoplasmonics,surface plasmon resonance,urinary tract infection,biosensing,uropathogenic E. coli,surface-relief gratings
更新于2025-09-23 15:21:01
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Surface Plasmon Resonance Based Recent Advances in Understanding Plant Development and Related Processes
摘要： Since its introduction in the early 1990s, SPR has now become a powerful research tool for studying specificity, affinity and real time kinetics of a broad range of biomolecular interactions, including protein-DNA, protein-protein, protein-carbohydrate, protein-RNA and protein-lipid interactions. Surface plasmon resonance (SPR) has provided crucial information on the mechanisms of molecular interactions accompanying varied aspects of plant development. The structure-function relationship of various lectins depends on the quaternary arrangement of its monomers. Novel findings have been made in plant hormone research using SPR as a technique. Thus, new salicylic acid binding proteins (SABPs) have been identified in Arabidopsis. These include α-ketoglutarate dehydrogenase E2 subunit, glutathione S-transferases, the oligopeptidases TOP2 and TOP1, and members of GAPDH protein family. By immobilizing biotin-labelled DELLA peptides on the sensor chip and AtGID1a [Arabidopsis gibberellic acid (GA) receptor] as analyte, GA4 has been observed to maximally enhance binding between DELLA and GID1. Molecularly imprinted monolayer (MIM)-decorated SPR detection method precisely differentiates between similar plant hormones, such as, IAA, 1H-indole-3-butyric acid (IBA) and kinetin (KT), with detection limits around sub-picomolar range. Coronatine Insensitive-1 (COI1) has been shown to act as a jasmonic acid receptor using SPR. Ricin, a plant toxin, was detected at a concentration 2,500 times less than the minimum lethal dose (200 ng.ml-1) using a SPR biosensor. Real time binding kinetic studies of viral proteins (VirE1 and VirE2) and ssDNA using SPR have shown that their binding is strongly influenced by substrate and it occurs at poly T sequences and not at polyA and dsDNA. An interaction between the replicase protein (p93) of cucumber necrosis tombusvirus (CNV) with the host protein, Hsp 70 (molecular chaperone), has revealed the potential role of Hsp90 in the assembly of viral replicase. SPR analysis from a small library of phytochemicals has shown ellagitannin geraniin as one of the most potent inhibitor of Hsp90 (a stabilizer of many oncoproteins). Future applications of SPR technique are likely to provide tremendous inputs into the molecular understanding of plant development and related processes.
关键词： Protein-chaperone interactions,Protein-carbohydrate interactions,Plant viruses,Surface plasmon resonance,Phytohormones,Protein-nucelic acid interactions,Xenobiotics,Protein-protein interactions
更新于2025-09-23 15:21:01
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Surface Plasmon Resonance-Enhanced Visible-NIR-Driven Photocatalytic and Photothermal Catalytic Performance by Ag/Mesoporous Black TiO2 Nanotubes Heterojunctions
摘要： Ag/mesoporous black TiO2 nanotubes heterojunctions (Ag-MBTHs) are fabricated through surface hydrogenation, wet-impregnation and photoreduction strategy. The as-prepared Ag-MBTHs possess a relatively high specific surface area of ~85 m2 g-1 and an average pore size of ~13.2 nm. The Ag-MBTHs with narrow bandgap of ~2.63 eV extend the photoresponse from UV to visible light and near-infrared (NIR) region, which exhibit excellent visible-NIR-driven photothermal catalytic and photocatalytic performance for complete conversion nitro aromatic compounds (100%) and mineralization of high-toxic phenol (100%). The enhancement can be attributed to the mesoporous hollow structures increasing the light multi-refraction, the Ti3+ in frameworks and the surface plasmon resonance (SPR) effect of plasmonic Ag nanoparticles favoring light-harvesting and spatial separation of photogenerated electron-hole pairs, which is confirmed by transient fluorescence. The fabrication of this novel SPR-enhanced visible-NIR-driven Ag-MBTHs catalyst may provide new insights for designing other high-performance heterojunctions photocatalytic and photothermal catalytic nanomaterials.
关键词： mesoporous black TiO2 nanotube,photothermal catalysis,surface plasmon resonance,Photocatalysis,heterojunction
更新于2025-09-23 15:21:01
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Broadband Plasmonic Polarization Filter Based on Photonic Crystal Fiber with Dual-Ring Gold Layer
摘要： Polarization ?lter is a very important optical device with extinction characteristics. Due to the design ?exibility of photonic crystal ?bers and the high excitation losses of the gold layer, the polarization ?lter based on the photonic crystal ?ber and surface plasmonic resonance e?ect is widely studied. Considering these, we present a simple and high-performance polarization ?lter using the ?nite element method. Numerical simulations show that there is a large di?erence in energy between the two polarization directions by reasonable adjustment of the structural parameters, the con?nement loss in the x-pol direction is less than that in the y-pol direction, which is suitable to realize a broadband polarization ?lter. When the ?ber length is 2 mm, the extinction ratio peak can reach ?478 dB, and the bandwidth with the extinction ratio better than ?20 dB is 750 nm, which covers communication wavelengths of 1.31 μm and 1.55 μm (1.05–1.8 μm). It also has a low insertion loss of 0.11 dB at 1.31 μm and 0.04 dB at 1.55 μm. In addition, our design has high feasibility in fabrication and better tolerance. The proposed ?lter with compactness, high extinction ratio, broad bandwidth, and low insertion loss would play an important role in the sensing detection, bio-medical, and telecommunication ?eld.
关键词： extinction ratio,photonic crystal ?ber,con?nement loss,polarization ?lter,surface plasmon resonance
更新于2025-09-23 15:21:01
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Ultrafast energy absorption and photoexcitation of bulk plasmon in crystalline silicon subjected to intense near-infrared ultrashort laser pulses
摘要： We investigate the non-linear response and energy absorption in bulk silicon irradiated by intense 12-fs near-infrared laser pulses. Depending on the laser intensity, we distinguish two regimes of non-linear absorption of the laser energy: for low intensities, energy deposition and photoionization involve perturbative three-photon transition through the direct bandgap of silicon. For laser intensities near and above 1014 W/cm2, corresponding to photocarrier density of order 1022 cm?3, we find that absorption at near-infrared wavelengths is greatly enhanced due to excitation of bulk plasmon resonance. In this regime, the energy transfer to electrons exceeds a few times the thermal melting threshold of Si. The optical reflectivity of the photoexcited solid is found in good qualitative agreement with existing experimental data. In particular, the model predicts that the main features of the reflectivity curve of photoexcited Si as a function of the laser fluence are determined by the competition between state and band filling associated with Pauli exclusion principle and Drude free-carrier response. The non-linear response of the photoexcited solid is also investigated for irradiation of silicon with a sequence of two strong and temporary non-overlapping pulses. The cumulative effect of the two pulses is non-additive in terms of deposited energy. Photoionization and energy absorption on the leading edge of the second pulse is greatly enhanced due to free carrier absorption.
关键词： bulk silicon,optical reflectivity,photoexcited solid,near-infrared laser pulses,Drude free-carrier response,non-linear response,energy absorption,plasmon resonance
更新于2025-09-23 15:21:01
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Recent advances of plasmonic nanoparticle-based optical analysis in homogeneous solution and at the single-nanoparticle level
摘要： Plasmonic nanoparticles with special localized surface plasmon resonance (LSPR) characters have been widely applied for optical sensing of various targets. With the combination of single nanoparticle imaging techniques, dynamic information of reactions and biological processes is obtained, facilitating the deep understanding of their principle and design of outstanding nanomaterials. In this review, we summarize the recently adopted optical analysis of diverse analytes based on plasmonic nanoparticles in both homogeneous solution and single-nanoparticle level. A brief introduction of LSPR is first discussed. Colorimetric and fluorimetric homogeneous detection examples by using different sensing mechanisms and strategies are provided. Single plasmonic nanoparticle-based analysis is concluded in two aspects: visualization of chemical reactions and understanding of biological processes. The basic sensing mechanisms and performances of these systems are introduced. Finally, this review highlights the challenges and future trend of plasmonic nanoparticle-based optical analysis system.
关键词： Plasmonic nanoparticles,Single-nanoparticle level,Fluorimetric assays,Chemical reactions,Localized surface plasmon resonance (LSPR),Optical analysis,Homogeneous solution,Colorimetric assays,Biological processes
更新于2025-09-23 15:21:01
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Fluorometric determination of morphine via its effect on the quenching of fluorescein by gold nanoparticles through a surface energy transfer process
摘要： A method is described for sensitive and selective fluorometric determination of morphine. It is based on the effect of morphine on quenching of the fluorescence of fluorescein by gold nanoparticles (AuNPs) via surface energy transfer. When fluorescein is added to solutions of colloidal AuNPs, its fluorescence becomes quenched due to nanometal surface energy transfer (NSET) because the absorption of AuNPs strongly overlaps the emission spectrum of fluorescein. In the presence of morphine, which contains both a tertiary nitrogen ring atom and a phenolic hydroxy group, it will coordinate to the AuNPs, and this causes recovery of fluorescence. The presence of a tertiary nitrogen ring atom and a phenolic hydroxy group (both required for the effect to occur) in morphine make the probe highly selective and sensitive for morphine. A paper strip assay also was developed by utilizing this detection scheme. The turn-on fluorescent probe was successfully applied to the determination of morphine in spiked serum and urine samples. The method has a 53 pM limit of detection. The paper strip was applied to the determination of morphine in sweat, urine and other biological fluids. It is perceived to be useful for early detection of drug abuse by adolescent.
关键词： Dynamic quenching,Neurotransmitter,Anesthetic drug,Paper-strip assay,Surface plasmon resonance,Stern-Volmer plot
更新于2025-09-23 15:21:01