Surface Plasmon Resonance Effect Research Articles

Localized surface plasmon resonance effect of bismuth nanoparticles in Bi/TiO2 catalysts for boosting visible light-driven CO2 reduction to CH4

Herein, the photocatalysts of metallic Bi-modified TiO2 microsphere (namely BTO) were synthesized by one-pot solvothermal method. The localized surface plasmon resonance (LSPR) effect of introduced metallic Bi nanoparticles is beneficial to improve the absorption efficiency for visible light, and its surface hot electrons can donate to the valence band of TiO2 for boosting the separation efficiency of light generated electron-hole pairs. BTO catalysts exhibit the super catalytic activity for visible light-driven CO2 reduction with H2O to CH4. The formation amount and selectivity of CH4 product over BTO-2 catalyst are 49.12 μmol g−1 and 85.48 % for 4 h, respectively. Based on the results of in-situ DRIFTS and density functional theory calculation, the mechanism for photocatalytic CO2 reduction is proposed: the visible light-driven LSPR effect on BTO catalyst can boost the key step of CO2* -to-HCO* for promoting selective generation of CH4 product. It inspires the design of efficient photocatalysts for CO2 conversion.

One-pot preparation of Bi/BiOF/Bi2O2CO3 Z-scheme heterojunction with enhanced photocatalysis activity for ciprofloxacin degradation under simulated sunlight

To improve the photocatalytic activity of BiOF under simulated sunlight irradiation, a ternary Bi-based Z-scheme heterojunction of Bi/BiOF/Bi2O2CO3 nanosheets were prepared using one-pot hydrothermal technique, where N, N-dimethylformamide was used as carbon source for Bi2O2CO3 and reductant for metal Bi, bismuth nitrate was employed as Bi source and NaF was used as F source. The photocatalytic activity of Bi/BiOF/Bi2O2CO3 was improved greatly towards ciprofloxacin degradation with the reaction kinetic constant of 0.0649 min−1, which was 7 and 3.5 times to that of BiOF and Bi2O2CO3, respectively. The improved photocatalytic activity was ascribed to the surface plasmon resonance effect of metal Bi and the synergistic effects of BiOF/Bi2O2CO3 Z-scheme heterojunction, which facilitated the migration of the photogenerated electron and inhibited the recombination of photogenerated e−/h+ pairs. The degradation mechanism and charge transfer pathway were confirmed. This work expands the application of BiOF-based photoactive materials in environmental field.

Ag-loaded BiFeO3/CuS heterostructured based composite: an efficient photocatalyst for removal of antibiotics and antibacterial activities.

The performance of advanced materials in environmental applications using green energy is the tremendous interest among researchers. The visible light responsive BiFeO3 (BFO), BiFeO3/CuS (BFOC), and Ag-loaded BiFeO3/CuS (Ag-BFOC) heterostructures have been synthesized by reflux method followed by hydrothermal and wetness impregnation method. These synthesized composites are well characterized through X-ray diffraction, UV diffuse reflectance spectroscopy, scanning electron microscope, and Fourier transfer infrared spectroscopy techniques. Compared with BFO and BFOC, Ag-BFOC exhibits the highest photocatalytic performance towards the degradation of antibiotics ciprofloxacin (76%) within 120-min time and also showed better antibacterial performance towards gram-negative (Escherichia coli, Klebsiella pneumoniae, and Acinetobacter baumannii) bacteria. Moreover, the novelty of the present work is the addition of CuS on the surface of BiFeO3 from heterojunction type II and facilitates the electron-hole channelization at the interfaces between BiFeO3 and CuS. Again, the loading of Ag on BiFeO3/CuS helps in shifting the absorption band towards the red end, is eligible to absorb more sunlight due to surface plasmon resonance effect, improves the separation efficiency of photo-generated charge carriers, and enhances the photocatalytic degradation of ciprofloxacin. The antibacterial property of Ag gives a best result towards antimicrobial activity. The prepared composites have proved their durability and stability by four successive cycles and prove the versatility of the composite.

Enhanced photocatalytic performance of 3d flower-like Ag@Ag2CO3/Bi2O2CO3 all-solid-state Z-scheme heterojunction

Heterojunction construction is an enduring topic for semiconductor photocatalytic performance enhancement. In this study, a novel Ag@Ag2CO3/Bi2O2CO3 heterojunction photocatalyst was prepared by precipitation method, in which Ag2CO3 nanorods was coated by Ag nanoparticles and 3D flower-like Bi2O2CO3. The Ag@Ag2CO3/Bi2O2CO3 all-solid-state Z-scheme photocatalytic system boosted the photocatalytic degradation of the sodium isobutyl xanthate and o-cresol, as compared to bare Bi2O2CO3 and Ag@Ag2CO3. Benefitting from the morphology modulation, the significant increase in photocatalytic activity of Ag@Ag2CO3/Bi2O2CO3 was achieved owing to the enhanced light-harvesting and increased specific surface area. The in-situ formed Ag0 nanoparticles simultaneously forms Z-scheme all-solid-state heterojunctions (Ag2CO3/Bi2O2CO3) and accelerates the photogenerated charge separation with surface plasmon resonance effect. A possible mechanism of 3D Ag@Ag2CO3/Bi2O2CO3 Z-scheme system with a strengthened photocatalytic performance was proposed based on the characterization results and trapping experiments.

The theranostic potential of green nanotechnology-enabled gold nanoparticles in cancer: A paradigm shift on diagnosis and treatment approaches

The application of nanotechnology to cancer research has resulted in substantial advancements. In this study, gold nanoparticles (AuNPs) synthesised utilising environmentally friendly methods are evaluated for their potential as multipurpose theranostic agents in cancer treatment. These eco-friendly AuNPs are attractive candidates for theranostic applications that combine diagnosis and therapy due to their specific physicochemical features. Green nanotechnology practises that use only sustainable, biocompatible materials promote biocompatibility in biomedical applications while reducing environmental impact. Imaging techniques such as optical coherence tomography, surface-enhanced Raman scattering, and photoacoustic imaging can benefit from AuNPs in part due to their optical properties. Their surface plasmon resonance (SPR) can be adjusted, improving imaging contrast and allowing for tailored administration of therapeutic payloads. The localised SPR effect of AuNPs also increases the efficacy of photothermal treatment (PTT) by converting near-infrared light into localised heat and inducing hyperthermia in cancer cells. Because of the localised heating, the cancer may be ablated precisely and with minimal collateral damage. AuNPs can be observed and assessed in real time as part of a multimodal imaging platform, in addition to being used as diagnostic and therapeutic tools. The primary focus of this research is on recent breakthroughs in the production of AuNPs using green nanotechnology techniques, particularly those that have occurred beyond 2020, and their potential applications in cancer theranostics. We are investigating various techniques for functionalizing AuNPs with specific ligands, medications, and imaging agents in order to improve therapeutic efficacy. We also go over the regulatory considerations and toxicity assessments that must be considered when bringing these nanomaterials into clinical use, as well as the potential that exist.

Synthesis of cobalt doped nickel titanate nanomaterials for enhanced photocatalytic reduction of chromium

A series of cobalt doped nickel titanate nanomaterials where cobalt % is varied from 1 to 10% have been successfully synthesized by solvothermal method followed by calcination at 600 °C. Synthesized materials are characterized by XRD, FE-SEM, HR-TEM, BET surface area, DRS UV-Vis-NIR, XPS and PL spectroscopy. XRD and HR-TEM confirm the existence of NiTiO3 ilmenite structure with crystallite size in the range of 20–30 nm. HR-TEM of cobalt doped NiTiO3 shows the presence of tiny single atom cobalt metal sitting on NiTiO3, surface which induces the surface plasmon resonance effect. XPS of the doped NiTiO3 exhibits Ti3+ formation accompanied with oxygen vacancies resulting in the extended light absorption in the Vis-NIR region. The photocatalytic efficiency is studied monitoring the photoreduction of carcinogenic Cr (VI) under visible light. 3% cobalt doped NiTiO3 achieves 100% reduction of 30 ppm Cr (VI) solution within 60 min whereas pristine NiTiO3 shows only 50% efficiency under identical conditions. The trapping experiment shows the direct transfer of photogenerated electrons for the reduction of Cr (VI) following a first order kinetics. The two-fold enhanced activity of cobalt doped NiTiO3 is due to the collective effect of oxygen vacancies, efficient Vis-NIR absorption and surface plasmon resonance effect.

D-shape Optical Fiber Development and Enhancement as a Refractive Indices Sensor Using Surface Plasmon Resonance

This article showcases the development and utilization of a side-polished fiber optic sensor that can identify altered refractive index levels within a glucose solution through the investigation of the surface Plasmon resonance (SPR) effect. The aim was to enhance efficiency by means of the placement of a 50 nm-thick layer of gold at the D-shape fiber sensing area. The detector was fabricated by utilizing a silica optical fiber (SOF), which underwent a cladding stripping process that resulted in three distinct lengths, followed by a polishing method to remove a portion of the fiber diameter and produce a cross-sectional D-shape. During experimentation with glucose solution, the side-polished fiber optic sensor revealed an adept detection sensitivity of 0.2015 au. /RIU. In order to improve sensitivity, a recent sensor was subjected to a coating process utilizing a thin film layer of gold (Au) measuring a thickness of 50 nm. The sensor was subsequently subjected to a series of tests utilizing the same glucose solutions as in previous experiments. A notable enhancement in sensitivity was observed when utilizing gold as the sensing material, with an equivalent maximum sensitivity of 3.101 au. /RIU.

Investigating the effect of adding silver nanoparticles to hybrid crystalline silicon solar cells

Hybrid silicon solar cells are an implementation of solar cells which have a simple fabrication process meanwhile absorbing a wider range of light spectrums compared to common silicon solar cells, although hybrid silicon solar cells have relatively low efficiencies. Metal nanoparticles have been known to enhance the performance of solar cells due to their localized surface plasmon resonance effect. The present study evaluates the addition of silver nanoparticles to enhance the properties and performance of hybrid silicon solar cells. In this regard silver nanoparticles are added to hybrid silicon solar cells producing different layer combinations in hybrid silicon solar cells. According to the results the addition of silver nanoparticles in specific combinations may enhance the performance whereas in other combinations may destroy the photovoltaic characteristics of the hybrid solar cell. A certain combination of the hybrid silicon solar cells including silver nanoparticles has been proposed wherein the properties of the cell are enhanced due to the plasmonic effect of silver nanoparticles. However, silver nanoparticles added on the surface of the photovoltaic cells cause shading, thus decreasing the active surface of the cell and thereby reducing the efficiency of the cells. Therefore, there is an optimum surface distribution for silver nanoparticles to benefit from the localized surface plasmon resonance effect meanwhile not shading a large amount of the cell and reducing the active surface area of the cell which is evaluated in the present research. Accordingly, by adding silver nanoparticles from a solution of 50% vl concentration the efficiency of the hybrid silicon cell reached 3.7% which is a significant increase compared to the efficiency of the ordinary hybrid silicon solar cells which was 1.8%.

A tunable graphene-based phase-jump inversion plasmonic sensor for ultra-sensitive refractive index sensing over THz frequency

The surface plasmon resonance effect has been previously reported as an essential mechanism for terahertz wave sensing applications. However, due to its structural geometric parameters dependence, either the reconfiguration of the arrays or the realignment of the prism system is required, which always remains one of the challenges limiting practical applications. Here, a graphene-based phase-jump inversion plasmonic sensor (GPPS) operating at a fixed gap and incident angle is established. The optimal wave vector matching between specific analytes and the GPPS can be achieved by adjusting the Fermi level of graphene. On this basis, an ultrahigh sensitivity of 0.488 THz/RIU is achieved under the optimal Fermi level. Remarkably, the comparison between the phase spectra and the reflective amplitude spectra indicates that the phase-based FoM and Q-factor are two orders of magnitude larger than those calculated by amplitude spectra, which could reach 244RIU−1 and 218.5. The unique phase-jump responses on graphene surface plasmon resonance provide new ideas for ultra-sensitivity THz sensing methods.

Plasmonic Au nanoparticles sensitized ZnO/CuO heterostructure for efficient photoelectrochemical water splitting

Hydrogen production via photoelectrochemical water splitting is a promising route to convert solar energy into chemical fuel, reducing energy crises and boosting environmental health. Here, we report the fabrication of ternary ZnO/CuO/Au heterostructures by electrodeposition and chemical bath deposition methods. The heterojunction formed can enhance the optical absorption, and photogenerated electrons and holes can efficiently separate due to the built-in electric field, which reduces recombination losses. Au plasmons incorporated in ZnO/CuO heterojunction enhance the optical absorption and promote fast free charge carrier transport at the interface through the surface plasmon resonance (SPR) effect. The ZnO/CuO/Au photoanode exhibits a photocurrent density of 1.08 mA/cm2 at 1.6 V Vs RHE, two times higher than pristine ZnO. The ZnO/CuO/Au photoanode exhibits the lowest charge transfer resistance of 600 Ω from electrochemical impedance spectra(EIS). The Bode plot revealed that the most extended lifetime of 8.69 μs is observed for ZnO/CuO/Au photoanode, which is larger than pristine ZnO. The synthesized thin films showed good stability and reusability for the photooxidation of water.

Fe3O4/carbon-decorated graphene boosts photothermal conversion and storage of phase change materials

Pristine organic phase change materials (PCMs) are difficult to complete photothermal conversion and storage. To upgrade their photothermal conversion and storage capacity, we developed Fe-MOF (metal-organic framework) derived Fe3O4/C-decorated graphene (GP) based composite PCMs toward solar energy harvesting. Graphene is an excellent phonon conductor, and Fe3O4/C-GP as a photon capturer exhibits strong full-spectrum absorption. Additionally, Fe-MOF derived Fe3O4 nanoparticles are anchored on graphene nanosheets to reduce interfacial thermal resistance, shorten thermal diffusion path, and accelerate phonon transport. After the encapsulation of octadecanol (ODA) in Fe3O4/C-GP, ODA@Fe3O4/C-GP composite PCMs yield a high photothermal conversion efficiency of 88.18 % under 0.12 W/cm2 benefiting from the synergistic effect of 3D interconnected graphene framework and Fe3O4 nanoparticles with localized surface plasmon resonance effect. Moreover, ODA@Fe3O4/C-GP composite PCMs exhibit excellent latent heat storage stability, photothermal conversion stability and durable reliability after undergoing multiple cycle evaluation, boosting high-efficiency utilization of solar energy.

Light-induced enhanced phase change process of plasmonic nanofluids: The reduction of the latent heat of vaporization

Recently, some studies have shown that the light-induced localized surface plasmon resonance (LSPR) effect of plasmonic nanoparticles can significantly influence the gas–liquid phase change process of nanofluids, but the mechanism is still not clear. In this work, we conducted several comparative experiments and molecular dynamics (MD) simulations to investigate the reduction of the latent heat of vaporization (LHV) of plasmonic nanofluids (PNFs) under the impact of the LSPR effect. During the experiments, gold nanofluids with different concentrations were comparatively heated using a heat gun and monochromatic incident lights, and the LHV was calculated based on the Clausius-Clapeyron equation. It is found that when the LSPR effect is excited, the LHV of gold nanofluids with high concentrations can be dramatically reduced by 60.2 % under the combined effect of thermal diffusion and enhanced electric field (EEF). To further investigate the impact of the LSPR-induced EEF on the gas–liquid phase change process of PNFs, a modified MD simulation was used for calculating the LHV of gold nanofluids. The result reveals that nanoparticles not only act as ‘heat sources’ that transfer the thermal energy to the surrounding liquid when the LSPR effect is excited but also can excite the EEF to directly accelerate the motion of liquid molecules from the liquid state to the gaseous state. This work clearly reveals that the LSPR-induced EEF plays a crucial role in both the evaporation and boiling process of PNFs.

Ag nanoparticles decorated ZnO nanopagodas for Photoelectrochemical application

Photoelectrochemical water splitting (PEC-WS) utilizing solar energy and photoelectrodes immersed in an electrolyte has sparked an increased interest in hydrogen production. The PEC-WS efficiency is enhanced by controlling the nanostructure of photoelectrodes and sensitizing them with plasmonic metals. This study shows how the transformation from ZnO nanorods to ZnO nanopagodas and the deposition of Ag nanoparticles improve the photocurrent and PEC conversion efficiency under sunlight. The deposition of an optimal amount of Ag nanoparticles over ZnO nanopagodas exhibited the highest photocurrent of 2.15 mA cm−2 at 1.23 V vs RHE, while pure ZnO nanorods and nanopagodas achieved 0.90 and 1.43 mA cm−2, respectively. This extraordinary improvement in photocurrent density was thoroughly analyzed using various PEC and optical measurements as well as electromagnetic simulation. As a result, two main reasons for the improvement were derived. Firstly, ZnO nanopagodas can reduce the charge recombination rate due to the reduced structural defects and improve the light-harvesting ability due to their distinct superstructure characteristics. Secondly, the deposition of plasmonic Ag nanoparticles can improve the interfacial charge transfer and increase the ability to capture visible light due to their localized surface plasmon resonance effects.

Plasmonic effect on the emission intensity of Ce3+ ions doped zirconia-silicate glass

Ce3+:SiO2-ZrO2 samples doped with and without plasmonic nanoparticles of copper were prepared by the easy and economic non-hydrolytic sol–gel method. Structural, morphological, and optical studies were done on the samples after being dried at room temperature and annealed at 800 °C. Fourier transform infrared (FTIR) spectra confirms the formation of the host glass SiO2-ZrO2 from the asymmetric stretching of Si-O-Zr bond. Tetragonal ZrO2 and plasmonic copper nanoparticles formation was affirmed from the X-ray diffraction (XRD) spectra. Transmission electron microscopy (TEM) confirms the formation of plasmonic nanoparticles of copper. UV/Visible spectra show an absorption around 330 nm. The photoluminescence (PL) spectra show emission centered around 469 nm; an enhancement in the PL intensity occurred due to the localized surface plasmon resonance (LSPR) effect of the plasmonic nanoparticles of copper.

Immobilized Z-scheme Ag|AgBr/Ag/FeTiO3 nanocomposite film photocatalyst for visible-light-driven photocatalytic degradation of norfloxacin with simultaneous hydrogen evolution and mechanism perspective

A novel immobilized Z-scheme Ag|AgBr/Ag/FeTiO3 nanocomposite film photocatalytic system was constructed, and applied within the photocatalytic degradation of norfloxacin with simultaneous hydrogen evolution under visible light. The photocatalytic performance of Z-scheme Ag|AgBr/Ag/FeTiO3 nanocomposite film was estimated. A series of factors affecting the photocatalytic activity of Ag|AgBr/Ag/FeTiO3 were investigated. The possible mechanism of the immobilized Z-scheme Ag|AgBr/Ag/FeTiO3 nanocomposite photocatalytic system was proposed. The results reveal that the Ag|AgBr/Ag/FeTiO3 system exhibits superior photocatalytic activity, due to the surface plasmon resonance effect produced by the Ag nanoparticles and the high separation efficiency of electron-hole pairs caused by the Z-scheme photocatalytic system. Importantly, the Z-scheme Ag|AgBr/Ag/FeTiO3 composite film is immobilized on the carrier, which facilitates the recycling and reuse of photocatalysts. The degradation extent of norfloxacin can reach 90.16%, and the hydrogen production can achieve 304.08 µmol within 180 min. Moreover, after five cycles, the Ag|AgBr/Ag/FeTiO3 photocatalyst possesses preeminent stability. During photocatalytic degradation, the hydroxyl radical plays a dominant role. Therefore, the immobilized Z-scheme Ag|AgBr/Ag/FeTiO3 photocatalytic technology holds good application value in the purification of antibiotics wastewater and the simultaneous hydrogen production.

Composites of W18O49 Nanowires with g-C3N4/RGO Nanosheets for Broadband Light-Driven Photocatalytic Wastewater Purification.

Developing a photocatalyst that can effectively utilize the full solar spectrum remains a high-priority objective in the ongoing pursuit of efficient light-to-chemical energy conversion. Herein, the ternary nanocomposite g-C3N4/RGO/W18O49 (CN/RGO/WO) was constructed and characterized by a variety of techniques. Remarkably, under the excitation of photon energies ranging from the ultraviolet (UV) to the near-infrared (NIR) region, the photocatalytic performance of the CN/RGO/WO nanocomposite exhibited a significant enhancement compared with single component g-C3N4 or W18O49 nanosheets for the degradation of methyl orange (MO). The MO photodegradation rate of the optimal CN/1.0 wt% RGO/45.0 wt% WO catalyst reached 0.816 and 0.027 min-1 under UV and visible light excitation, respectively. Even under low-energy NIR light, which is not sufficient to excite g-C3N4, the MO degradation rate can still reach 0.0367 h-1, exhibiting a significant enhancement than pure W18O49. The outstanding MO removal rate and stability were demonstrated by CN/RGO/WO nanocomposites, which arise from the synergistic effect of localized surface plasmon resonance effect induced by W18O49 under vis-NIR excitation and the Z-scheme nanoheterojunction of W18O49 and g-C3N4. In this work, we have exploited the great potential of integrating nonmetallic plasmonic nanomaterials and good conductor RGO to construct high-performance g-C3N4-based full-solar spectral broadband photocatalysts.

Intrinsic Polarized Electric Field Induces a Storing Mechanism to Achieve Energy Storing Catalysis in V2 C MXene.

Efficient storage and separation of holes and electrons pose significant challenges for catalytic reactions, particularly in the context of single-phase catalysis. Herein, V2 C MXene, with its intrinsic polarized electric field, successfully overcomes this obstacle. To enhance hole storage, a multistep etching process is employed under reducing conditions to control the content of surface termination groups, thus exposing more defective active sites. The intrinsically polarized electric field confines holes to the surface of the layer and free electrons within the layer, leading to a lag in e- release compared to h+ . The quantities of stored holes and electrons are measured to be 18.13µmolg-1 and 106.37 µmol g-1 , respectively. Under dark, V2 C demonstrates excellent and stable dark-catalytic performance, degrading 57.91% of tetracycline (TC 40mg L-1 ) and removing 23% of total organic carbon (TOC) after 140 min. In simulated sunlight and near-infrared light, the corresponding degradation rates reach 72.24% and 79.54%, with corresponding TOC removal rates of 49% and 48%, respectively. The hole and electron induced localized surface plasmon resonance (LSPR) effects contribute to a long-lasting and enhanced broad-spectrum mineralization of V2 C MXene. This study provides valuable insights into the research and application of all-weather MXene energy storage catalytic materials.

SERS and machine learning based effective feature extraction for detection and identification of amphetamine analogs

Surface-enhanced Raman spectroscopy (SERS) is extensively researched in diverse disciplines due to its sensitivity and non-destructive nature. It is particularly considered a potential and promising technology for rapid on-site screening in drug detection. In this investigation, a technique was developed for fabricating nanocrystals of Ag@Au SNCs. Ag@Au SNCs, as the basic material of SERS, can detect amphetamine at concentrations as low as 1 μg/mL. The Ag@Au SNCs exhibits a strong surface plasmon resonance effect, which amplifies molecular signals. The SERS spectra of ten substances, including amphetamine and its analogs, showed a strong peak signal. To establish a qualitative distinction, we examined the Raman spectra and conducted density functional theory (DFT) calculations on the ten aforementioned species. The DFT calculation enabled us to determine the vibrational frequency and assign normal modes, thereby facilitating the qualitative differentiation of amphetamines and its analogs. Furthermore, the SERS spectrum of the ten mentioned substances was analysed using the support vector machine learning algorithm, which yielded a discrimination accuracy of 98.0 %.

Tungsten Nitride with a Two-Dimensional Multilayer Structure for Boosting the Surface-Enhanced Raman Effect.

The development of high-performance surface-enhanced Raman scattering (SERS) substrates is an urgent and important task. Here, tungsten nitride (WN) with a two-dimensional (2D) multilayer structure has been successfully prepared through a nitriding WO2.90 precursor. In addition to the highly active "hot spots" formed on the surface of the WN sheets, a large number of gaps between the nanosheets also exhibit a strong local surface plasmon resonance effect, which greatly improves the SERS activity. Evaluated as the SERS substrate, the WN with a 2D multilayer structure exhibits good SERS characteristics and good homogeneity and stability, even after strong acid, strong alkali, or long-term light treatment. Significantly, typical environmental contaminants such as dichlorophenol and butylated hydroxyanisole also exhibit strong Raman enhancement signals. This research provides a new method for designing inexpensive, high-activity, and universal SERS substrates.

SPR Biosensor Sensor principle and application progress

SPR Biosensor, full name Surface Plasmon Resonance Biosensor, is an instrument used to detect biomolecular interactions. It has the advantages of high sensitivity, high selectivity and real-time to monitor the interaction between substances in real time by optical principle. The working principle of SPR biosensor is based on surface plasmon resonance effect. When there is a certain refractive index difference between the metal surface and the medium, the incident light will be reflected and transmitted. When a biological molecule or chemical molecule binds to a metal surface, it changes the refractive index of the surface, which causes the Angle and intensity of the reflected light to change. By monitoring the changes in reflected light, the binding process and properties of substances can be obtained. SPR biosensors can be widely used in biomedical fields, such as drug screening, disease diagnosis, protein interaction research and so on. Its simple principle, high sensitivity and strong real-time performance make it one of the indispensable tools in modern biological science research. The development direction of SPR biosensor mainly includes improving sensitivity and selectivity, expanding application field, reducing cost and so on. At present, many improved technologies and methods have emerged, such as the introduction of nanomaterials, microfluidic technology, etc., to improve the performance and practicality of sensors. In conclusion, SPR biosensor is an important bioanalytical instrument with broad application prospects and plays an important role in biomedical research and clinical diagnosis.