Application Of Surface Plasmon Resonance Research Articles

The Rapid Detection of Paclitaxel-Induced Changes in Cervical Cancer Cells Using an Ultrasensitive Biosensor

Background: Paclitaxel is a widely used cancer treatment drug that has a significant inhibitory effect on cervical cancer cells (HeLa cells). This study aims to investigate the effects of paclitaxel on HeLa cells and evaluate the application of terahertz (THz) spectroscopy and surface plasmon resonance (SPR) biosensors in this process. Methods: We utilized an SPR biosensor in conjunction with THz spectroscopy to measure the terahertz absorbance spectra of HeLa cells exposed to various concentrations of paclitaxel. The minimum number of cells used for detection was 15.25 × 105. At the same time, cell proliferation levels were assessed through proliferation assays and compared with the terahertz spectroscopy data. Results: The experimental results indicated that with the increasing concentration of paclitaxel, the terahertz absorbance spectra of HeLa cells exhibited a blue shift, and cell proliferation was significantly inhibited. The results of the proliferation assays were consistent with the terahertz spectroscopy data, validating the effectiveness of this method. Conclusion: This study demonstrates that the combination of THz spectroscopy and SPR biosensors is a promising technology that can provide a simple, rapid, and low-cost method for studying chemistry–biology relationships, especially in the field of drug evaluation.

Recent Developments on Optical Aptasensors for the Detection of Pro‐Inflammatory Cytokines with Advanced Nanostructures

AbstractIn the realm of immune response, pro‐inflammatory cytokines play a crucial role in regulating various physiological functions. Accurate measurement of these low‐molecular‐weight proteins is essential for understanding immune function, predicting diseases, and monitoring treatment effects. Optical aptasensors with advanced nanostructures, which utilize aptamers as bio‐probes, have emerged as a promising technology for cytokine detection, offering advantages over traditional antibody‐based nanobiosensors. Aptamers, single‐stranded nucleic acids with high specificity and affinity, enable cost‐effective mass production and consistent quality. Optical biosensors incorporating aptamers exhibit stability, resistance to environmental factors, and prolonged functionality. This review explores the current methodologies and advancements in optical aptasensors for cytokine detection, highlighting their potential as robust tools in diagnostics and therapeutics. Specifically, the applications of surface plasmon resonance and fluorescence techniques in aptasensors are discussed, focusing on the innovative approaches used to enhance sensitivity and specificity in cytokine detection. Notable examples of aptasensor designs utilizing nanoparticles, Förster resonance energy transfer, and amplification strategies are presented. These designs demonstrate high affinity, specificity, and improved sensitivity in detecting pro‐inflammatory cytokines such as interferon gamma. Overall, optical aptasensors show great promise in advancing the understanding of cytokine‐related disorders and enabling effective interventions.

Applications of Surface Plasmon Resonance (SPR) to the Study of Diverse Protein-Ligand Interactions.

Functional characterization of enzymes/proteins requires determination of the binding affinity of small molecules or other biomolecules with the target proteins. Several available techniques, such as proteomics and drug discovery strategies, require a precise and high-throughput assay for rapid and reliable screening of potential candidates for further testing. Surface plasmon resonance (SPR), a well-established label-free technique, directly measures biomolecular affinities. SPR assays require immobilization of one interacting component (ligand) on a conductive metal (mostly gold or silver) and a continuous flow of solution containing potential binding partner (analyte) across the surface. The SPR phenomenon occurs when polarized light excites the electrons at the interface of the metal and the dielectric medium to generate electromagnetic waves that propagate parallel to the surface. Changes in the refractive index due to interaction between the ligand and analyte are measured by detecting the reflected light, providing real-time data on kinetics and specificity. A prominent use of SPR is identifying compounds in crude plant extracts that bind to specific molecules. Procedures that utilize SPR are becoming increasingly applicable outside the laboratory setting, and SPR imaging and localized SPR (LSPR) are cheaper and more portable alternative for in situ detection of plant or mammalian pathogens and drug discovery studies. LSPR, in particular, has the advantage of direct attachment to test tissues in live-plant studies. Here, we describe three protocols utilizing SPR-based assays for precise analysis of protein-ligand interactions. © 2024 Wiley Periodicals LLC. Basic Protocol 1: SPR comparison of binding affinities of viral reverse transcriptase polymorphisms Basic Protocol 2: SPR screening of crude plant extract for protein-binding agents Basic Protocol 3: Localized SPR-based antigen detection using antibody-conjugated gold nanoparticles.

Synergistic effect of ZnO Thin Films with Gold as Antifungal Coatings

Microbial contamination on surfaces is a problem worldwide, affecting public health and industry. The increasing prevalence and severity of microbial infection outbreaks across various environments have highlighted the urgent need to develop antimicrobial coatings/surfaces to mitigate the risk of disease transmission through high‐touched surfaces. This work focuses on assessing the antifungal activity of thin films based on zinc oxide (ZnO), produced by reactive magnetron sputtering with varying thicknesses, and evaluating the impact of varying gold concentrations within the ZnO matrix on both microstructure and antifungal activity. The developed thin films exhibit noteworthy antifungal activity against the fungus Candida albicans, achieving 80% reduction in cell viability, regardless of thickness and gold concentration (up to 15.4 at%). Annealing treatment at 600 °C induces the formation of large and irregular gold nanostructures (sizes from 39 to 260 nm), enhancing the antifungal activity compared to the as‐deposited samples. This highlights the surface‐dependent antifungal efficacy of ZnO‐based thin films and a synergistic effect when combined with gold. Additionally, the thin films not only exhibit antifungal activity but also demonstrate potential for localized surface plasmon resonance applications. Overall, ZnO‐based thin films hold promise as antifungal coatings for diverse surfaces, offering a preventive measure against microbial contamination.

Surface plasmon resonance-mediated photocatalytic H2 generation.

The limited yield of H2 production has posed a significant challenge in contemporary research. To address this issue, researchers have turned to the application of surface plasmon resonance (SPR) materials in photocatalytic H2 generation SPR, arising from collective electron oscillations, enhances light absorption and facilitates efficient separation and transfer of electron-hole pairs in semiconductor systems, thereby boosting photocatalytic H2 production efficiency. However, existing reviews predominantly focus on SPR noble metals, neglecting non-noble metals and SPR semiconductors. In this review, we begin by elucidating five different SPR mechanisms, covering hot electron injection, electric field enhancement, light scattering, plasmon-induced resonant energy transfer, and photo-thermionic effect, by which SPR enhances photocatalytic activity. Subsequently, a comprehensive overview follows, detailing the application of SPR materials-metals, non-noble metals, and SPR semiconductors-in photocatalytic H2 production. Additionally, a personal perspective is offered on developing highly efficient SPR-based photocatalysis systems for solar-to-H2 conversion in the future. This review aims to guide the development of next-gen SPR-based materials for advancing solar-to-fuel conversion.

Surface Plasmon Resonance Application for Bacteria Pathogen Detection: A Minireview

Detection of pathogenic bacteria requires a fast and accurate process so technological developments related to the sensitivity and selectivity of a sensor are very concerned. Surface Plasmon Resonance (SPR) technology has great potential to detect pathogenic bacteria that are not only used for medical diagnostics, but food safety surveillance and environmental monitoring are also applications of SPR. The success of SPR has proven the advantages of real-time detection without the need for fluorescent markers or additional dyes. The development of sensor surface systems of SPR with nanomaterials is one of the discussions in this paper. The recent development of SPR in recent years is summarized by linking future prospective applications.

Experimental study of SPR sensor performance enhancement by metal oxides

With the widespread application of fiber surface plasmon resonance (SPR) sensors in the field of biochemical sensing, especially in the detection of large molecules such as proteins, the sensitivity of traditional fiber SPR sensors has made it difficult to meet the requirements of detection accuracy in practical applications. This article proposes and proves an effective method for selecting the optimal metal oxide material to improve the sensing performance of SPR sensors. Metal oxides (TiO2 and ZnO) can improve the sensitivity by enhancing the evanescent field of fiber SPR phenomenon. Through simulation, it was found that when the metal oxide film of the composite film sensor maintains the same thickness, the metal oxide with a high effective refractive index (RI) has a better improvement effect on the sensitivity of the SPR sensor. Experimental results show that the maximum RI sensitivity of TiO2 composite film sensors and ZnO composite film sensors in the RI range of 1.333–1.420 is 15,200 nm/RIU and 13,600 nm/RIU, respectively. Compared to silver-based sensors, RI sensitivity has increased by 16.92 % and 4.62 %, respectively. To further verify the enhancement effect of different metal oxides on fiber sensors, another layer of PDMS film is deposited on TiO2 and ZnO films. Within the temperature sensing range, the maximum temperature sensitivity of these two composite film temperature sensors is 4.9 nm/°C and 4.3 nm/°C, respectively. Overall, metal oxides with high RI can improve the sensing performance of fiber optic sensors.

Application of the localized surface plasmon resonance of silver nanoparticles for the determination of ethion in water samples

Application of the localized surface plasmon resonance of silver nanoparticles for the determination of ethion in water samples

Surface plasmon resonance induced methane gas sensor in hollow core anti-resonant fiber

Optical fiber sensors based on surface plasmon resonance (SPR) have been widely studied for their low cost, anti-electromagnetic interference, and remote sensing. To our best knowledge, the applications of SPR in anti-resonant optical fiber for gas sensing has not been reported before. In this study. We numerically investigated a methane gas sensor based on SPR in Hollow core anti-resonant fiber (HC-ARF) using the finite element method. Six gold films were coated on the inner wall of six anti-resonant tube in HC-ACF, while an ultraviolet-cured fluoro-siloxane nano-films containing cage molecule A were further coated on the surface of six gold films as the methane gas-sensitive film. Simulation results showed that the methane gas measurement sensitivity reached 5.54 nm/% at the methane gas concentration of 0–3.5%. Our work which greatly improves the sensitivity in SPR based optical fiber methane gas sensing can be used for the early warning of methane gas leakage.

Low-Energy Photons Dual Harvest for Photocatalytic Hydrogen Evolution: Bimodal Surface Plasma Resonance Related Synergism of Upconversion and Pyroelectricity.

Utilization of low-energy photons for efficient photocatalysis remains a challenging pursuit. Herein, a strategy is reported to boost the photocatalytic performance, by promoting low-energy photons dual harvest through bimodal surface plasmon resonance (SPR)-enhanced synergistically upconversion and pyroelectricity. It is achieved by introducing triplet-triplet annihilation upconversion (TTA-UC) materials and plasmonic material (Au nanorods, AuNRs) into composite fibers composed of pyroelectric substrate (poly(vinylidene fluoride)) and photocatalyst Cd0.5 Zn0.5 S. Interestingly, the dual combination of TTA-UC and AuNRs SPR in the presence of polyvinylidene fluoride substrate with pyroelectric property promotes the photocatalytic hydrogen evolution performance by 2.88folds with the highest average apparent quantum yield of 7.0% under the low-energy light (λ > 475nm), which far outweighs the role of separate application of TTA-UC (34%) and AuNRs SPR (76%). The presence of pyroelectricity plays an important role in the built-in electric field as well as the accordingly photogenerated carrier behavior in the composite photocatalytic materials, and the pyroelectricity can be affected by AuNRs with different morphologies, which is proved by the Kelvin probe force microscopy and photocurrent data. This work provides a new avenue for fully utilizing low-energy photons in the solar spectrum for improving photocatalytic performance.

Universal and flexible design for high-sensitivity and wide-ranging surface plasmon resonance sensors based on a three-dimensional tuning hypersurface

Surface plasmon resonance (SPR), generally including propagating SPR (PSPR) and localized SPR (LSPR), has attracted wide attention due to the uniqueness of the strong evanescent field. The PSPR has the merit of high sensitivity over the LSPR, but lacks flexibility to tune resonant wavelength and serves limited application. Here we revisit the fundamental PSPR wavevector matching theory and construct a three-dimensional (3D) tuning hypersurface for the parameters of resonant wavelength, incident angle, and surrounding refractive index, which provides the performance tuning guide map. With assistance of the hypersurface, a hypersurface-tuning PSPR (HT-PSPR) sensor is designed with high sensitivity and ultra-wide detection range. Experiments demonstrate that the sensor can selectively tune the resonance and render the sensitivity to a theoretical upper limit of ∼105 nm/RIU, or an ultra-wide detection range of 0.518 RIU, which satisfies the requirement for most gas and liquid sensing applications. Using D-biotin as the detection sample of small molecule (MW=244 Da), the HT-PSPR sensor achieves an ultra-low detection limit down to 27.5 fM. The hypersurface-tuning has created an intrinsic, universal and flexible method for tuning PSPR at the desired resonant wavelength, sensitivity and detection range, which is expected to find great significance in SPR design and applications.

Utility of SPR technology in biotherapeutic development: Qualification for intended use

Surface plasmon resonance (SPR) analysis provides important binding characteristic information for an antibody to its binding partner, such as binding specificity and affinity (KD). In recent years, SPR has been increasingly used in biosimilar development as part of the comparative analytical similarity assessment. Although there is no systematic study describing how to qualify SPR assays, there are various SPR result types (outputs) that have been used for assay qualification in publicly available regulatory documents. The mixed usage of SPR output can cause confusion and can be misleading when comparing binding attributes among antibody molecules. In this report, using a recombinant huIgG1 (mAb 1) antibody as an example, we performed assay qualification strictly based on the nature of the biomolecular interaction. We recommend that KD should be used as the output of assay qualification when the KD can be measured accurately by SPR. When KD cannot be accurately determined in a SPR setting, sensorgram comparison and Parallel Line Analysis (PLA) can be used to qualify the assay. We emphasize the importance of setting up appropriate SPR assay conditions for target and/or Fc receptor interactions to ensure the assay qualification parameters, such as accuracy and repeatability, to meet the criteria acceptable for regulatory filings. With increasing numbers of biotherapeutics being developed, the methods and guidelines provided here can help to align SPR application between the drug development industry and regulatory authorities which will benefit the scientific communities involved in biotherapeutic drug development.

Applications of surface plasmon resonance in biomedicine

As one of optical technique, surface plasmon resonance (SPR) shows a superb interdisciplinary usage for detection. A diverse of different SPR-based biosensors have been constructed and been used for various fields, such as biomedicine, environmental monitoring and food safety. This research outlines the basic concepts, the working principle of SPR and the applications of SPR in biomedicine. In addition, the discovery and development of SPR will be present, as well as the mechanism behind SPR instruments. It will also be examined in detail the application of SPR in drug analysis and early diagnosis of cancer. Some perspectives about the latest research advances and future development areas will also be discussed respectively. The advantages and disadvantages of SPR will be illustrated throughout this work.

Applications of Surface Plasmon Resonance and Biolayer Interferometry for Virus-Ligand Binding.

Surface plasmon resonance and biolayer interferometry are two common real-time and label-free assays that quantify binding events by providing kinetic parameters. There is increased interest in using these techniques to characterize whole virus-ligand interactions, as the methods allow for more accurate characterization than that of a viral subunit-ligand interaction. This review aims to summarize and evaluate the uses of these technologies specifically in virus–ligand and virus-like particle–ligand binding cases to guide the field towards studies that apply these robust methods for whole virus-based studies.

Optical properties of formation of gold nanoparticle aggregates deposited on quartz glass and application to SPR sensing

The sensing of surrounding medium is a research focus, which is highly dependent on the nanotechnology that exhibits typical features of technical difficulty and high price. In this work, a surrounding medium sensor based on gold nanoparticles (Au NPs) is fabricated. The formation of Au NP aggregates is deposited on quartz glass by alternately immerses the glass sheet in positive charged cationic polymer polyethyleneimine and negative charged citrate coated Au NPs. The formation of Au NP aggregates with different numbers of NPs is fabricated controlling numbers of deposition and deposition time. The formation of aggregates contains less NPs exhibit ability of refractive index sensing by monitoring the surface plasmon resonance (SPR) of Au NPs. The formation of Au NP aggregates can be used as a substitute of Au NPs array for the application of SPR sensing for the merits of easy fabrication and low cost.

Microscopies Enabled by Photonic Metamaterials.

In recent years, the biosensor research community has made rapid progress in the development of nanostructured materials capable of amplifying the interaction between light and biological matter. A common objective is to concentrate the electromagnetic energy associated with light into nanometer-scale volumes that, in many cases, can extend below the conventional Abbé diffraction limit. Dating back to the first application of surface plasmon resonance (SPR) for label-free detection of biomolecular interactions, resonant optical structures, including waveguides, ring resonators, and photonic crystals, have proven to be effective conduits for a wide range of optical enhancement effects that include enhanced excitation of photon emitters (such as quantum dots, organic dyes, and fluorescent proteins), enhanced extraction from photon emitters, enhanced optical absorption, and enhanced optical scattering (such as from Raman-scatterers and nanoparticles). The application of photonic metamaterials as a means for enhancing contrast in microscopy is a recent technological development. Through their ability to generate surface-localized and resonantly enhanced electromagnetic fields, photonic metamaterials are an effective surface for magnifying absorption, photon emission, and scattering associated with biological materials while an imaging system records spatial and temporal patterns. By replacing the conventional glass microscope slide with a photonic metamaterial, new forms of contrast and enhanced signal-to-noise are obtained for applications that include cancer diagnostics, infectious disease diagnostics, cell membrane imaging, biomolecular interaction analysis, and drug discovery. This paper will review the current state of the art in which photonic metamaterial surfaces are utilized in the context of microscopy.

A Review: Surface Plasmon Resonance-Based Biosensor for Early Screening of SARS-CoV2 Infection

Rapid viral diagnosis is essential to contain the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) in the community and ensure effective patient management. However, the current gold standard for diagnosis of viral disease depends on the time-consuming molecular technique. Surface plasmon resonance (SPR) phenomenon has been widely applied in the analysis of biomolecular interactions and analytes detection, which is currently being investigated as a quick diagnostic method of numerous viral infections. In this regard, researchers have performed experimental studies dedicated to enhancing the sensitivity and specificity of the SPR sensor performance for utilization in the medical diagnostic field. In this review, we summarized various SPR application including the recent advancements and advantages of different types of SPR-based biosensor such prism-based, localized surface plasmon resonance (LSPR), fiber optic, optical grating, and optical waveguide for the detection of SARS-CoV2. We proposed various technical recommendations to improve the sensitivity, accuracy, time response, and cost-saving means of the SPR sensor. A special focus was set for sensitivity enhancement aspects in terms of the type of prism, nanomaterials, support layer with type and shape of optical fibers for early, swift, and ultra-sensitive detection of viral infection. With the highlighted impacts of SPR application, this review frames the current potential and challenges of SPR in comparison to the current gold standard of viral infection diagnostic strategy.

On the Use of Surface Plasmon Resonance-Based Biosensors for Advanced Bioprocess Monitoring

Biomanufacturers are being incited by regulatory agencies to transition from a quality by testing framework, where they extensively test their product after their production, to more of a quality by design or even quality by control framework. This requires powerful analytical tools and sensors enabling measurements of key process variables and/or product quality attributes during production, preferably in an online manner. As such, the demand for monitoring technologies is rapidly growing. In this context, we believe surface plasmon resonance (SPR)-based biosensors can play a role in enabling the development of improved bioprocess monitoring and control strategies. The SPR technique has been profusely used to probe the binding behavior of a solution species with a sensor surface-immobilized partner in an investigative context, but its ability to detect binding in real-time and without a label has been exploited for monitoring purposes and is promising for the near future. In this review, we examine applications of SPR that are or could be related to bioprocess monitoring in three spheres: biotherapeutics production monitoring, vaccine monitoring, and bacteria and contaminant detection. These applications mainly exploit SPR’s ability to measure solution species concentrations, but performing kinetic analyses is also possible and could prove useful for product quality assessments. We follow with a discussion on the limitations of SPR in a monitoring role and how recent advances in hardware and SPR response modeling could counter them. Mainly, throughput limitations can be addressed by multi-detection spot instruments, and nonspecific binding effects can be alleviated by new antifouling materials. A plethora of methods are available for cell growth and metabolism monitoring, but product monitoring is performed mainly a posteriori. SPR-based biosensors exhibit potential as product monitoring tools from early production to the end of downstream processing, paving the way for more efficient production control. However, more work needs to be done to facilitate or eliminate the need for sample preprocessing and to optimize the experimental protocols.

Bio-inspired self-assembly of large area 3D Ag@SiO2 plasmonic nanostructures with tunable broadband light harvesting

Tremendous efforts have been made to fabricate large-scale plasmonic nanostructures, which show wide applications in surface plasmon resonance (SPR) sensing, catalytic conversion, photothermal conversion, optoelectronics, photothermal therapy. However, unable to fabricate over 5 cm2 plasmonic nanostructures with good controllability hinders their further applications. Here, super large-scale (153 cm2) 3D Ag@SiO2 hybrid plasmonic nanostructures with adjustable and ultra-broadband light absorption are fabricated by a simple and controllable two-step approach. The metastable atomic layer deposition (MS-ALD) is combined with physical vapor deposition (PVD) to generate these structures in a self-assembly manner. The structures look like coral tentacles. These excellent properties are attributed to multiple forward scatterings and extinction effects produced by Ag@SiO2 nanostructures. Using 3D Ag@SiO2 plasmonic nanostructures as light absorber for bottom-heating-based evaporation, the water evaporation rate remarkably improves seven times under 1 Sun than that in dark condition. Our results pave the avenue for developing super large-scale Ag-based plasmonic nanostructure with potential applications in solar energy conversion.

Surface plasmon assisted toxic chemical NO<sub>2</sub> gas sensor by Au ∕ ZnO functional thin films

Abstract. In this short communication, we propose a surface plasmon resonance (SPR) sensor based on a ZnO / Au hybrid thin-film material structure and experimentally investigate its sensitivity improvement. The Kretschmann-based SPR sensor utilizes ZnO thin films and nanostructures for performance enhancement. The advancement in SPR technology relies on a low-cost, high-sensitivity, and high-selectivity sensor. Metal oxide (MO) has been incorporated into the SPR sensor to be used for detection of biological and chemical compounds. ZnO as one of the metal oxides is an attractive material due to its unique physical and optical properties. Numerous techniques for fabrication and characterization of ZnO on SPR gold substrate have been studied. The mechanism for gas and biomolecule detection depends on their interaction with the ZnO surface, which is mainly attributed to the high isoelectric point of ZnO. There are several types of ZnO nanostructures which have been employed for SPR application based on the Kretschmann configuration. In the future, the thin film and nanostructures of ZnO could be a potential application for miniature design, robust, high sensitivity, and a low-cost portable type of SPR biosensor to be used for on-site testing in a real-time and label-free manner. The present work includes the application of a developed SPR setup for gas sensing at room temperature using a specially designed gas cell. The change in the optical properties of dielectric layers (ZnO) with adsorption of gases (NO2) in order to develop an optical sensor has been presented. The obtained results emphasize the applications of an SPR setup for the study of interaction of adsorbed gas molecules, with dielectrics and gas sensing.