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.

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.

Design of a Surface-Plasmon-Resonance Sensor Based on a Microstructured Optical Fiber with Annular-Shaped Holes

A novel design is proposed for highly sensitive surface-plasmon-resonance sensors. The sensor is based on a microstructured optical fiber with two layers of annular-shaped holes. A gold layer is deposited on the inner surface of the second hole-layer, in which the holes have several micrometers thickness in size, facilitating analyte infiltration and metal layer deposition. In the first layer of holes, the sector-ring^shaped arms, used as supporting strips, are utilized to tune the resonance depth of the sensor. Numerical results indicate that the sensor operation wavelength can be tuned across the C＋L-band. The spectral sensitivity of 1.0.104 nm. RIU-1 order of magnitude and a detection limit of 1.0.10-4 RIU order are demonstrated over a wide range of analyte refractive index from 1.320 to 1.335.

Surface Plasmon Resonance Sensors Based on Polymer Optical Fiber

Surface Plasmon Resonance （SPR） is a powerful technique for directly sensing in biological studies, chemical detection and environmental pollution monitoring. In this paper, we present polymer optical fiber application in SPR sensors, including wavelength interrogation surface enhanced Raman scattering SPR sensor and surface enhanced Raman scattering （SERS） probe. Long-period fiber gratings are fabricated on single mode polymer optical fiber （POF） with 120 μm period and 50% duty cycle. The polarization characteristic of this kind of birefringent grating is studied. Theoretical analysis shows it will be advantageous in SPR sensing applications.

Numerical study of a highly sensitive surface plasmon resonance sensor based on circular-lattice holey fiber

A new design of surface plasmon resonance(SPR)sensor employing circular-lattice holey fiber to achieve highsensitivity detection is proposed.The sensing performance of the proposed sensor is numerically investigated and the results indicate that our proposed SPR sensor can be applied to the near-mid infrared detection.Moreover,the maximum wavelength sensitivity of our proposed sensor can reach as high as 1.76×10^(4)nm/refractive index unit(RIU)and the maximum wavelength interrogation resolution can be up to 5.68×10^(-6)RIU when the refractive index(RI)of analyte lies in(1.31,1.36).Thanks to its excellent sensing performance,our proposed SPR sensor will have great potential applications for biological analytes detection,food safety control,bio-molecules detection and so on.

波长调制型PMMA光波导SPR传感器敏感单元设计

光波导表面等离激元共振(SPR)传感器具有尺寸小、免标记、易集成等优点。文章设计了一种基于波长调制方法的聚甲基丙烯酸甲酯(PMMA)脊型波导SPR传感器,并对其关键参数进行了优化。结果表明,该敏感单元在待测液折射率为1.33~1.45的范围内能够稳定工作,在高折射率检测区,传感器展现出了高达10220nm/RIU的灵敏度和173RIU^(-1)的高品质因数。

Sensitivity enhancement of WS2-coated SPR-based optical fiber biosensor for detecting glucose concentration

In this paper,we propose a theoretical model of the surface plasmon resonance-based optical fiber biosensor for detecting glucose concentration.The Au/ZnO/WS2 multilayer film is coated around optical fiber.Compared with the conventional surface plasmon resonance sensor,WS2 material can increase the sensitivity of the biosensor.The absorption capacity of WS2 is used to load glucose oxidase by forming a sensitive area to recognize glucose.Refractive index of the solution is calculated and then the concentration of the glucose can be obtained by the correspondence between refractive index and glucose concentration.The highest sensitivity of the SPR biosensor with a structure of 40-nm Au/5-nm ZnO/14 layers of WS2 is 4310 nm/RIU.The proposed WS2-based SPR fiber biosensor has a unique effect on the detection of glucose concentration.It is expected to have potential applications in future medical blood glucose concentration detection.

基于SPR的重金属离子检测技术研究进展

重金属离子浓度的检测对于人体健康和环境科学等领域具有重要意义。与其它离子检测方法相比,表面等离子体共振(surface plasmon resonance,SPR)技术具有无标记,灵敏度高和检测限低等优点,为重金属离子监测领域带来了新的可能性。本文综述了SPR传感技术在重金属离子检测中的应用及其技术进展。首先介绍了SPR传感的技术原理;然后在传感材料的选择以及表面修饰等方面,针对铅、汞等有害重金属离子,重点阐述了对灵敏度、线性动态范围和特异性等指标的改进;最后介绍了SPR成像传感技术在检测速度、灵敏度等方面取得的重大进展,展望了SPR技术的发展前景。

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.

基于新型拼接光子晶体光纤的SPR葡萄糖浓度传感器

针对人体血糖的稳定高效检测问题,本文提出了一种基于表面等离子体共振(SPR)技术的光纤传感器并成功应用于葡萄糖浓度检测。采用光纤熔接机级联拼接多模光纤–光子晶体光纤–光子晶体光纤–多模光纤(MPPM),利用磁控溅射仪在光纤结构表面沉积金膜。随后,使用巯基乙胺对传感区的金膜进行修饰,采用戊二醛固定葡萄糖氧化酶(GOD)的技术路线,使传感器具备葡萄糖特异性识别功能,并实现对低浓度葡萄糖溶液的传感。针对SPR传感器的折射率灵敏度,本文设计两组对比实验,分别是相同结构不同传感区长度的传感器对比,以及相同长度不同结构的传感器对比。研究结果表明:传感区长度对传感器的折射率灵敏度的影响较小;MPPM传感结构的折射率灵敏度优于MPM传感结构(提高了约101.84 nm/RIU),且MPPM结构的传感器具有更深的SPR共振峰,意味着检测精度更高。对于制备的葡萄糖传感器,设计了一套葡萄糖浓度、特异性识别及稳定性的检测方案。实验结果表明:在0~0.8 mg/mL的浓度范围的葡萄糖溶液中,MPPM传感器的葡萄糖灵敏度约为29.61nm/(mg·mL^(–1)),且表现出良好的线性关系,拟合系数达到了0.954;具有良好的特异性识别能力及稳定性能。相比于传统的葡萄糖传感器,本文提出的葡萄糖传感器结构紧凑、生物相容性好、灵敏度高。

Fiber cladding SPR bending sensor characterized by two parameters

A fiber cladding surface plasmon resonance(SPR)bending sensor is realized by the cladding of the fiber structure.By employing coating film,the sensing zone is protected and the toughness of the sensor increases.Three different sensing probes are tested,the experiment results indicate that the two parameters(wavelength sensitivity and light intensity sensitivity)sensing performances of the eccentric butt joint structures are superior to that of hetero-core structure,and the SPR bending sensor based on hetero-core structure is stable and uneasy to damage.By employing hetero-core fiber and silver film,a fiber cladding SPR bending sensor with better stabilization and sensing performance is realized.The proposed fabricating method of sensing probe with coating film provides a new approach for fiber SPR-distributed bending sensor.

Sensing characteristics of a metal film coated long-period fiber grating

To obtain the influence rules of the coating parameters of a long-period fiber grating(LPFG)with respect to temperature,strain and refractive index sensing properties,based on the mode coupling theory,a strict four-layer theorietical model of a metal film coated LPFG is established,and these parameters that affect the spectral characteristics of the metal film coated LPFG are studied.The simulation results show that there is an optimal metal film thickness on the surface of the LPFG that will induce the surface-plasmon resonance(SP R)effect,which results in higher sensitivity to the environmental temperature and refractive index but has little influence on the strain There is theoretical evidence that when the silver thickness is between0.8and1.2nm,the refractive index sensitivity will reach the peak point of42.4026,at which the refractive index sensor sensitivity is increased by4.S%.The theoretical results of coating a long-period fiber grating provide a good theoretical basis and guidance for LPFG design and parameters optimization

A Photonic Crystal Fiber Based Asymmetric Slotted Structured Highly Sensitive Refractive Index Plasmonic Biosensor

Surface plasmon resonance (SPR) sensors have grown in popularity owing to their sensitivity, precision, and capacity for a variety of applications, including detection, monitoring, and sensing, among others. Sensitivity and resolution are two areas where this technology has room for development. A plasmonic biosensor based on an asymmetric slotted PCF structure with extremely high sensitivity has been described and theoretically investigated. This high performance sensor is constructed and completely characterized using finite element method in COMSOL Multiphysics software environment. Sensitivity and resolution are analyzed as performance parameters for the proposed sensor. Numerical simulation exhibits the maximum wavelength-sensitivity of 1100 nm/RIU with 9.09 × 10-6 RIU resolution in the broad measurement range of refractive index from 1.30 to 1.44. A polarization controller can be used to fine-tune this extremely sensitive and wide-ranging refractive index sensor to fulfil a variety of practical needs. This is performed with the consideration of the variation in the refractive index (RI) of the analyte channels. In comparison with earlier PCF-based sensors, the fiber design structure is basic, symmetrical, simple to produce, and cost-effective. Because of the asymmetric air holes and higher sensitivities of the refractive index detector, it is possible to identify biomolecules, biochemicals and other analytes.

微纳光纤-金膜-氟化镁结构的光纤SPR温度传感器研究

为了提高光纤表面等离子共振温度传感器检测的适用条件,减少传感器对待测传感参量折射率的限制,避免引入对温度敏感的低折射率媒介,本文中将具有大倏逝场的微纳光纤放置于蒸镀金属膜的氟化镁衬底上,得到光纤表面等离子共振温度传感器结构。结果表明:通过使用传输矩阵的理论模型计算该结构中光纤折射率和氟化镁折射率变化对透射率影响,结合光纤和氟化镁的热光系数,分别得到约118、35 pm/℃的温度灵敏度,在光纤折射率增大对透射谱产生蓝移和氟化镁折射率增大对透射谱产生红移的共同作用下,该传感结构综合得到约153 pm/℃的传感器灵敏度。通过计算明确金膜厚度、光纤直径和光纤-金膜接触区宽度等不同的结构参量对透射率的影响。

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。

D型环光子晶体光纤表面等离子体共振传感器

提出了一种中红外波段宽范围低折射率检测的D型环双芯光子晶体光纤表面等离子体共振传感器。该结构为一个D型环,并在其内外表面都沉积一层金属层。采用全矢量有限元方法分析了该传感器的性能。结果表明,该传感器可以在中红外波段实现低折射率传感,并具有高传感灵敏度特性。分析物的折射率可检测范围为1.20~1.38,平均波长灵敏度和最大波长灵敏度可分别达到13717 nm/RIU和21150 nm/RIU,分辨率可达到1.94×10^(-5) RIU。该传感器可在化学、生物以及环境检测等领域有重要的应用。

Distributed optical fiber surface plasmon resonance sensors

The relationships of the resonant wavelength of optical fiber surface plasmon resonance （SPR） sensors to the modulation layer refractive index, thickness and the refractive index of the bulk medium are obtained by using theoretical calculation model of optical fiber SPR sensors under certain conditions, which indicates that resonant wavelength of the sensors is approximately linear with modulation layer thickness. Based on the linear relationship, multiple SPR sensors with different resonant wavelengths can be fabricated in a single optical fiber named as distributed optical fiber surface plasmon resonance sensors （DOFSPRSs）. Experimental results are presented, showing that it is practical to fabricate more than one SPR sensors in a single optical fiber.

基于SPR光谱分析的液体折射率测量研究

文章从电磁场理论和射线理论的角度,详细讨论了光纤表面等离子体波传感器工作原理,分析了表面等离子体共振(SPR)光谱共振波长与液体介质折射率之间的对应关系。采用相关光谱检测技术,获得八种不同类型分析醇所对应的SPR光谱曲线族,其共振波长随液体折射率的增大而逐渐向长波长方向偏移。通过对乙醇与乙二醇混合液体所对应的共振光谱分析,实现对两者配比浓度的测定。整个传感系统结构简单,测量光路部分实现全光纤化,不仅能够对目标测量介质的实时、快速、精确测量,还可用于特殊测量场合,实现远程遥测功能。

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 。

SPR传感器的应用及其发展

表面等离子共振(SPR)传感器是一项新兴的生物化学检测技术,具有灵敏度高、检测方便快捷、可实现在线检测等许多优点,可广泛应用于材料科学、环境保护、食品工业等直接关系人类生存发展的诸多领域。首先介绍了SPR传感器的发展历史及其工作原理,然后综述了SPR传感器的结构和分类,具体包括棱镜耦合式SPR传感器、集成光波导耦合式SPR传感器、光纤SPR传感器和光栅耦合式SPR传感器的结构,着重描述了SPR传感器的最新发展趋势,重点介绍了分布式SPR传感器、光纤SERS传感器的发展状况。