Fiber cladding dual channel surface plasmon resonance sensor based on S-type fiber

Fiber cladding surface plasmon resonance(SPR)sensors have few structures,and a clad SPR sensor based on S-type fiber is proposed in this paper.This new type of fiber cladding SPR sensor was formed by electrofusing an S-shaped structure on the fiber to couple the light in the fiber core to the cladding.In this paper,the effects of fiber parameters on the performance of the sensor were studied by simulation and experiment.Based on the conclusion that the smaller the core diameter is,the closer the working band of the SPR resonance is to long wavelengths,and that the geometric characteristics mean that a multimode fiber can receive the fiber cladding light from a small core diameter few-mode fiber,a dual channel SPR sensor with a double S-type fiber cascade was proposed.In the refractive index detection range of 1.333–1.385refractive index units(RIU),the resonant working band of channel I is 627.66 nm–759.78 nm,with an average sensitivity of 2540.77 nm/RIU,and the resonant working band of channel II is 518.24 nm–658.2 nm,with an average sensitivity of2691.54 nm/RIU.The processing method for the S-type fiber cladding SPR sensor is simple,effectively solving the problem of this type of SPR sensor structure and the difficult realization of a dual channel.The sensor is expected to be used in the fields of medical treatment and biological analysis.

Dual-channel fiber-optic surface plasmon resonance sensor with cascaded coaxial dual-waveguide D-type structure and microsphere structure

To address the restriction of fiber-optic surface plasmon resonance(SPR) sensors in the field of multi-sample detection, a novel dual-channel fiber-optic SPR sensor based on the cascade of coaxial dual-waveguide D-type structure and microsphere structure is proposed in this paper. The fiber sidepolishing technique converts the coaxial dual-waveguide fiber into a D-type one, and the evanescent wave in the ring core leaks, generating a D-type sensing region;the fiber optic fused ball push technology converts the coaxial dual waveguides into microspheres, and the stimulated cladding mode evanescent wave leaks, producing the microsphere sensing region. By injecting light into the coaxial dual-waveguide middle core alone, the sensor can realize single-stage sensing in the microsphere sensing area;it can also realize dual-channel sensing in the D-type sensing area and microsphere sensing area by injecting light into the ring core. The refractive index measurement ranges for the two channels are 1.333–1.365 and 1.375–1.405, respectively, with detection sensitivities of 981.56 nm/RIU and 4138 nm/RIU. The sensor combines wavelength division multiplexing and space division multiplexing technologies, presenting a novel research concept for multi-channel fiber SPR sensors.

Using a Surface Plasmon Resonance Biosensor for Rapid Detection of Salmonella Typhimurium in Chicken Carcass

Chicken is one of the most popular meat products in the world. Salmonella Typhimurium is a common foodbome pathogens associated with the processing of poultry. An optical Surface Plasmon Resonance （SPR） biosensor was sensitive to the presence of Salmonella Typhimurium in chicken carcass. The Spreeta biosensor kits were used to detect Salmonella Typhimurium on chicken carcass successfully. A taste sensor like electronic tongue or biosensors was used to basically ＂taste＂ the object and differentiated one object from the other with different taste sensor signatures. The surface plasmon resonance biosensor has potential for use in rapid, real-time detection and identification of bacteria, and to study the interaction of organisms with dif- ferent antisera or other molecular species. The selectivity of the SPR biosensor was assayed using a series of antibody con- centrations and dilution series of the organism. The SPR biosensor showed promising to detect the existence of Salmonella Typhimurium at 1 x 106 CFU/ml. Initial results show that the SPR biosensor has the potential for its application in pathogenic bacteria monitoring. However, more tests need to be done to confirm the detection limitation.

Analysis of 17β-Estadiol from Sewage in Coastal Marine Environment by Surface Plasmon Resonance Technique

In this study, surface plasmon resonance （SPR） for monitoring 17β-eatradiol （E2） was developed. The small molecule E2 was immobilized on a CM5 sensor chip for an indirect competitive immunoassay to detect E2. The SPR response bahed on the antigen-antibody reaction was measured by injecting the sample solution into the flow system. The limitation of detection was 0.445 μg/L. The developed SPE-SPR system was applied to analyze the seawater samples. Recovery of E2 was 91.6%-93. 1%. Relative standard deviations（RSD） for the E2 assay were between 10.9%-15.1% （n = 3）. The range of determination of E2 samples from the sewage in the coastal marine environ-ment was between ND（lower than detection limit） and ca. 11.78 ng/L.

Detection of Penicillin via Surface Plasmon Resonance Biosensor

A method of using Au colloid to capture the decomposed product of penicillin, penicillamine, on a surface plasmon resonance（SPR） biosensor for the quantitative determination of penicillin was developed. Based on the de-composition of penicillin to generate penicillamine and penilloaldehyde, a high sensitive biosensor for detecting penicillin was also developed. In our experiment, it was penicillamine rather than penicillin that has been measured. This is because penicillamine contains a functional group that makes it self-assembling on Au colloid to increase the molecular weight so as to improve the surface plasmon resonance signal. On a UV-Vis spectrophotometer, a high concentration of penicilliamine-Au complex was determined, indicating that penicillamine was already well combined with Au colloid. The method, using the combination of Au colloid with penicillamine, proved to detect penicillin.

Advances in Phase Detection Technique of Surface Plasmon Resonance Biosensor

Surface plasmon resonance (SPR) sensing is an optical method based on evanescent wave.SPR biosensor can detect interaction of label-free biomolecules in real-time.With further development,it can become a research instrument in proteomics.SPR biosensor can be divided intensity measurement and phase measurement,and the latter possesses higher sensitivity than the former one.This paper attempts to summarize the SPR phase detection theory,discuss the major developments,compare the merits and deficiencies of various methods,and look forward to future prospects.

Characteristics of Surface Plasmon Resonance Imaging lnterferometer

In recent life science research,identifying and characterizing entire biomolecular interaction networks is prerequisite to understanding cellular processes on a molecular and biophysical level.A surface plasmon resonance (SPR) imaging interferometer based on spatial phase modulation detection is presented to meet this demand.In this method,the SPR sensing chip surface is illuminated with collimated parallel light beam,and a Wollaston prism is introduced into the reflected light path to produce the interference of polarized light reflected from SPR sensing chip.Information of biomolecular interactions can be obtained by extracting the phase change from the SPR interference patterns.Using our interferometer,we made experiments on a series concentration of NaCl solutions to investigate its detection range,linearity,sensitivity and resolution.The results indicate that the SPR imaging interferometer is mainly sufficient for biomolecular interaction detection.

基于SPR效应的深刻蚀微开口双芯对称D型PCF传感器

为了进一步提升生物传感器传感性能,设计了一种基于表面等离子共振(SPR)效应的深刻蚀微开口双芯对称D型光子晶体光纤(PCF)传感器。该传感器采用堆叠、拉伸技术和化学气相沉积(CVD)技术制备,具有2种不同直径的气孔,且这2种气孔呈对称结构。介绍了采用该传感器的葡萄糖浓度检测系统原理,仿真分析了金属材料、气孔参数、抛光参数对传感器性能的影响。仿真结果表明,当折射率检测范围为1.26~1.41时,传感器的最大波长灵敏度、分辨率和葡萄糖浓度检测灵敏度分别可达24600 nm/RIU、4.06×10^(-6)RI U和2.73 nm/(g·L^(-1))。

Surface plasmon resonance sensor based on molecularly imprinted films for the detection of pentaerythritol tetranitrate （PETN）

A novel surface plasmon resonance （SPR） sensor based on molecularly imprinted films （MIFs） was developed for the detection of pentaerythritol tetranitrate （PETN）. In this work, the thin MIFs were formed on a gold sensor chip through thermal co-polymerization of functional mono- mers （methacrylic acid, MAA） and crosslinking monomers （ethylene glycol dimethacrylate, EGD- MA） in the presence of template molecules PETN. The template molecules PETN were subsequently removed from the MIFs simply by rinsing the MIFs with a mixture of acetonitrile and acetic acid 9：1 （ v/v）, thus the recognition sites were formed for specific detection of PETN. According to the mass coverage equation, the surface coverage of removed PETN from MIFs was about 10. 8 ng/mm~. The developed SPR sensor allowed for the detection of PETN at concentration down to 10-~~ mol/L. A control experiment utilizing an analogue cyclotrimethylenetrinitramine （RDX） showed MIFs＇ good selectivity to PETN.

Improvement of the Specificity of Surface Plasmon Resonance with BSA-modified Chip

A chip was modified with bovine serum albumin （BSA）, then interaction between glutathione （GSH） immobilized on the top of BSA and glutathione-S-transferase （GST） was examined, using surface plasmon resonance （SPR）. The SPR results showed that BSA-modified chip was effective not only in binding the target proteins but also in suppressing the nonspecific binding （NSB） of proteins.

Development and Application of Time-Resolved Surface Plasmon Resonance Spectrometer

Surface plasmon resonance (SPR) sensor, an optical sensor exploiting special electromagnetic waves-surface plasmon polaritons to probe interactions between an analyte in solution and a molecular recognition element immobilized on the SPR sensor surface, has been widely used in various realms, such as investigating biomolecular interactions and binding properties, detection of biological and chemical analytes, environmental monitoring, food safety and medical diagnostics. This paper reviews the development of SPR sensors and SPR commercial instruments, and emphatically introduces the time-resolved surface plasmon resonance (TR-SPR) techniques. The excellent performances of high sensitivity and rapid detection are easily achieved with TR-SPR spectrometer, whereas the traditional SPR spectrometer cannot be accomplished. Therefore, TR-SPR spectrometer is appropriate for real time analysis of bio-recognition events and small molecular dynamics. However, only two commercial TR-SPR instruments have been exhibited at present, Thermo FT-SPR 100 and Autolab ESPRIT (SPRINGLE). Unfortunately, the high-priced instruments are not suitable for extensive applications in laboratories at present. Herein, a novel commercial TR-SPR spectrometer has been introduced in this review.

Review of Fiber-Optic Localized Surface Plasmon Resonance Sensors:Geometries,Fabrication Technologies,and Bio-Applications

Localized surface plasmon resonance(LSPR)biosensors,which enable nanoscale confinement and manipulation of light,offer the enhanced sensitivity and electromagnetic energy localization.The integration of LSPR with the fiber-optic technology has led to the development of compact and versatile sensors for miniaturization and remote sensing.This comprehensive review explores various sensor configurations,fiber types,and geometric shapes,highlighting their benefits in terms of sensitivity,integration,and performance improvement.Fabrication techniques such as focused non-chemical bonding strategies and self-assembly of nanoparticles are discussed,providing control over nanostructure morphology and enhancing sensor performance.Bio-applications of fiber-optic LSPR(FOLSPR)sensors are detailed,specifically in biomolecular interactions and analysis of proteins,pathogens and cells,nucleic acids(DNA and RNA),and other small molecules(organic compounds and heavy metal ions).Surface modification and detection schemes are emphasized for their potential for label-free and real-time biosensing.The challenges and prospects of FOLSPR sensors are addressed,including the developments in sensitivity,fabrication techniques,and measurement reliability.Integration with emerging technologies such as nanomaterials is highlighted as a promising direction for future research.Overall,this review provides insights into the advancements and potential applications of FOLSPR sensors,paving the way for sensitive and versatile optical biosensing platforms in various fields.

Research on Fiber Optic Surface Plasmon R esonance.Biosensors:A Review

Due to the benefits of the high sensitivity,real-time response,no labeling requirement,and good selectivity,fiber optic sensors based on surface plasmon resonance(SPR)have gained popularity in biochemical sensing in recent years.The current research on such sensors is hot in enhancing sensitivity,improving detection accuracy,and achieving the detection of biochemical molecules.The goal of this work is to present a thorough overview of recent developments in the optical fiber SPR biosensor research.Firstly,it explores the basic principles and sensing structures of optical fiber SPR biosensors,focusing on four aspects.Subsequently,this paper introduces three fiber optic surface plasmon biosensors:SPR,localized surface plasmon resonance(LSPR),and long-range surface plasmon resonance(LRSPR).Each concept is explained from the perspective of the basic principles of fiber optic SPR biosensors.Furthermore,a classification of fiber optic SPR biosensors in health monitoring,food safety,environmental monitoring,marine detection,and other applications is introduced and analyzed.Eventually,this paper summarizes the current research directions of SPR biosensors.Meanwhile,it provides a prospective outlook on how fiber optic SPR sensors will develop in the future.

Surface plasmon polaritons frequency-blue shift in low confinement factor excitation region

Surface plasmon polaritons'(SPPs')frequency blue shift is observed in finite-difference time-domain(FDTD)simulation of parallel electron excitation Au bulk structure.Comparing with cold dispersion of SPPs,an obvious frequency blue shift is obtained in low confinement region excitation simulation results.Then,according to SPPs'transverse attenuation characteristics,the excited frequency mode instead of cold dispersion corresponding frequency mode matches it.Thence,this excited mode is confirmed to be SPPs'mode.As is well known the lower the frequency,the smaller the confinement factor is and the lower the excitation efficiency,the wider the bandwidth of excited SPPs is.And considering the attenuation in whole structure,the excited surface field contains attenuation signal.In a low confinement factor region,the higher the SPPs'frequency,the higher the excitation efficiency is,while broadband frequency information obtained in attenuation signal provides high frequency information in stimulation signal.Thence,in the beam-wave interaction,as the signal oscillation time increases,the frequency of the oscillation field gradually increases.Thus,compared with cold dispersion,the frequency of excited SPP is blueshifted This hypothesis is verified by monitoring the time domain signal of excited field in low and high confinement factor regions and comparing them.Then,this frequency-blue shift is confirmed to have commonality of SPPs,which is independent of SPPs'material and structure.Finally,this frequency-blue shift is confirmed in an attenuated total reflection(ATR)experiment.Owing to frequency dependence of most of SPPs'devices,such as coherent enhancement radiation and enhancement transmission devices,the frequency-blue shift presented here is of great influence in the SPPs applications.

纳米金用于SPR传感器检测小分子的研究进展

近年来,表面等离子体共振(Surface Plasmon Resonance,SPR)技术因具有可实时、动态监测SPR芯片上分子间相互作用的优点,而广泛应用于小分子传感检测领域。信号放大是小分子SPR传感器的重要研究内容,它决定小分子能否被检出及传感器灵敏度,因此信号放大技术对其发展非常重要。纳米金因其高电子密度、介电特性及易修饰等特性而用于多种传感器的信号放大。重点介绍近5年来纳米金在小分子SPR传感器方面的应用情况,旨在为小分子SPR传感器的进一步发展提供参考依据。

群智能优化的动态基线调整在光纤SPR传感器信号处理中的应用

将谱宽(β)、基线下测量点数(m)、面积比(λ)作为最佳动态基线的选择依据,在两级适应度函数条件下,利用粒子群优化算法跟踪β、m、λ,寻找最佳组合参数下的动态基线,有效克服了传统基线选择较为随意的问题。搭建了光纤SPR测试装置,采集8种不同浓度的蔗糖标准溶液的光谱数据,将4种质心跟踪法进行实验对比。结果表明群智能优化动态基线法的预测精度和相关性均最好,可以有效提取质心参数,消除光源波动对测试结果的影响,为实现光纤SPR实时在线监测提供了一种有效途径,其共振波长拟合度为0.996 3,RMSE为1.78。另外,考察了三种质心计算参数的主导地位,结果表明:在设定相同适应度情况下,固定m方法效果最好,进而为质心参数的选择控制提供有效依据。

SPR传感技术的发展与应用

SPR传感器已经成为检测、分析生物分子相互作用的有效工具。有些国家已经生产出商业化的SPR传感系统。对SPR生物传感器的研究现状、工作原理、技术参数与分类进行了详细描述,并对SPR生物传感器在生物分子检测领域的应用和SPR传感技术的研究发展前景进行了讨论。

SPR生物传感器及其应用进展

基于表面等离子体共振 (SPR)技术的光学生物传感器是进行生物分子相互作用分析的一种先进手段。与传统的超速离心、荧光法等相比 ,它具有实时检测、无需标记、耗样最少等特点 ,在药物筛选、临床诊断、食物及环境监控和膜生物学等领域中的新兴应用日益扩大 ,并且已成为生命科学和制药研究的一种标准的生物物理学工具。综述了近几年国际上生物传感器的应用进展情况 。

波长型SPR检测仪的灵敏度探讨

利用自行设计构建的可变入射角的波长型表面等离子体共振(SPR)检测仪,在不同浓度的蔗糖溶液中测定了不同入射角度(80°～66°)的共振曲线,经过处理得到共振峰位、半高宽及灵敏度随入射角和样品折射率变化的三维图像.在此基础上探讨了波长型SPR检测仪的主要参数对仪器性能的影响,从理论和实验上证明了影响灵敏度的主要因素为共振波长,并且随着共振波长的增大,检测灵敏度迅速提高.

利用SPR生物传感器检测牛奶中的氨苄青霉素残留

近年来,在食品安全检测领域,利用表面等离子体共振(surface plasmon resonance,SPR)传感器结合免疫测定方法进行痕量物质检测的技术得到了迅速发展。本文采用表面等离子共振生物传感器检测牛奶中的氨苄青霉素残留。从pH值、离子浓度和配体浓度三个方面讨论了实验条件对配体在传感器表面固定的影响,实验结果表明pH值为4.5、离子浓度为10mM以及配体浓度为400μg.mL-1为较佳实验条件。在此实验条件下对BSA-氨苄青霉素偶联物进行了固定,并采用该传感器对不同浓度的氨苄青霉素的水溶液和牛奶溶液进行了检测,最低检测限LOD分别为1.7ng.mL-1和1.8ng.mL-1,均低于氨苄青霉素的最大残留检测限(maximum residue limit,MRL)4.1ng.mL-1,验证了检测方法的可行性。