In this paper, a graphene-coated surface plasmon resonance sensor is designed for the examination of Rodent urine which is responsible for Leptospirosis bacteria. Rodent urine is considered as sensing medium. Graphene surface is activated by phosphate-buffered saline solution for better attachment of Leptospirosis bacteria on its surface. Oliguria and Polyuria are the Rodent urine with high and low concentrations of Leptospirosis bacteria, respectively. The transfer matrix method is used for the formulation of reflection intensity of p-polarized light. The reflectance curves for angular interrogation are plotted and the results are obtained in terms of sensitivity, detection accuracy, and quality factor. The significantly high sensitivity and detection accuracy for Oliguria distinguishes it from Polyuria having lower sensitivity.

The purpose of this work is to investigate theoretically the characteristics of confined electromagnetic modes propagating along the interfaces of a multilayer device. This one dimensional (1D) sensor is formed by stacking a left-handed material (LHM) layer between a SiO₂-glass prism and a dielectric gap layer in contact with gold (Au). The results indicate that the total thickness of the LHM layer and dielectric gap, in optimum conditions, give the ability of tuning significantly the characteristics of the resonant modes correlated to surface plasmons (SPs) propagation along the interfaces of the designed device. By considering two arrangements between LHM and Au, two opposite resonant behaviors observed in p-reflectance spectra are analyzed in the angular interrogation mode and discussed thoroughly.

An improved glucose sensitive membrane (GSM) is prepared by immobilizing glucose oxidase (GOD) onto a mixture of silica mesocellular foams (SiMCFs) and SiO2 nanoparticles (SiNPs) and then trapping it in a polyvinyl alcohol (PVA) gel. The membrane is coated onto a gold-glass sheet to create a surface plasmon resonance (SPR) sensor. A series of experiments are conducted to determine the optimized parameters of the proposed GSM. For a GSM with a component ratio of SiMCFs : SiNPs = 7 : 3 (mass rate), the resonance angle of the sensor decreases from 68.57° to 63.36°, and the average sensitivity is 0.026°/(mg/dL) in a glucose concentration range of 0 mg/dL-200 mg/dL. For a GSM with a component ratio of SiMCFs : SiNPs = 5 : 5 (mass rate), the resonance angle of the sensor decreases from 67.93° to 63.50°, and the sensitivity is 0.028°/(mg/dL) in a glucose concentration range of 0 mg/dL - 160 mg/dL. These data suggest that the sensor proposed in this study is more sensitive and has a broader measurement range compared with those reported in the literature to date.

In this paper, we present and discuss a path to extend the enhancement of the resolution of an optical surface plasmon resonance (SPR) sensor. Basically, our approach is to combine bi-metamaterial layers to design the SPR sensor. The calculation shows that the proposed SPR sensor structure has a preference over the conventional SPR sensors and bimetallic SPR sensors since it gives a much sharper reflectance dip and can achieve considerable sensitivity improvement when compared to the recently reported investigations. The effects of the metamaterial permittivity, permeability, and thickness on the reflectance curve are studied. It is also seen that metamaterial layers improve the field of the proposed SPR structure, which may provide a novel tool to significantly enhance the sensitivity and resolution of the sensors.

开发了一种多孔分子印迹膜修饰的表面等离子体共振(SPR)传感器,用于快速检测水中微囊藻毒素LR.研究了利用该传感器检测微囊藻毒素LR的方法.首先,通过原位聚合法在SPR传感芯片的裸金表面合成了微囊藻毒素LR的多孔分子印迹膜,制备出可以特异性捕获微囊藻毒素LR的SPR传感芯片.然后,利用Kretschmann棱镜耦合结构,构建了基于Kretschmann结构的波长调制型表面等离子体共振传感器.最后,通过检测不同浓度的微囊藻毒素LR溶液以及干扰物质微囊藻毒素RR溶液,研究了该传感器的测量范围、特异性等参数.结果表明,该传感器对于微囊藻毒素LR的检测灵敏度很高,可实现微囊藻毒素LR的定量检测,动态测量达2.1×10-9~1×10-6 mol/L.另外,传感器对于干扰物质微囊藻毒素RR无明显信号响应,表明传感器对于微囊藻毒素LR具有很好的特异性检测能力.

利用纳米压印结合溅射和反应离子刻蚀工艺制备了具有高深宽比的金光栅, 使用傅里叶变换红外光谱仪测得了反射谱线.测量结果显示,只在p偏振光垂直于光栅矢量方向入射条件下才存在共振反射峰, 证明了“伪表面等离子体激元波”的存在.基于严格耦合波分析理论计算了金属光栅的反射率, 研究了其作为中红外波段波长调制型表面等离子体共振传感器的可行性.数值计算表明负级次衍射光波对应的共振反射峰的移动能获得较高的波长灵敏度.对于深宽比为10的金光栅结构, +1级次和-3级次衍射光波对应的波长灵敏度分别为1600 nm/RIU和5000 nm/RIU, 品质因子分别为20 RIU-1和60 RIU-1.

对通过棱镜耦合的太赫兹表面等离激元共振传感器的工作特性进行了理论分析。 此类器件在可见光波段工作时, 在由样品折射率、 金属膜层性质和厚度决定的共振角度下会出现一个反射极小峰； 但工作在太赫兹频率时, 表面等离激元共振现象表现为一个反射增强的尖峰, 而且这一共振角度与棱镜和样品的折射率之间存在一个简单的对应关系, 并不依赖于棱镜所镀金属膜层的性质与厚度。 考虑到生物分子在太赫兹频率存在与其微观结构相关的电磁响应, 该探测器在生物和医学领域的科学研究和应用中将有独特的应用价值。

提出了利用光子晶体光纤空气孔塌缩技术制作光子晶体光纤表面等离子体共振传感器,构建了空气孔完全塌缩的光子晶体光纤表面等离子体共振传感器模型，并模拟计算了其中的表面等离子体共振效应。制作了全光纤化的波长检测型的光子晶体光纤表面等离子体共振传感器,利用超连续谱光源进行了相关实验。实验结果表明:以空气为待测环境介质时，对应的共振波长为465 nm，与理论计算相符合。

研究了一种基于波分复用原理的准分布式光纤表面等离子体波传感器。应用光波导理论和多层膜反射理论分析了表面等离子体波效应在同一光纤探头中连续被激励的原理及其传感模型。通过数值模拟和相应实验分别考察了蒸镀调制层对表面等离子体波共振(SPR)效果的影响, 并在此基础上给出了设计的一般步骤和原则。实验结果表明, 蒸镀不同厚度的Ta2O5薄膜将导致表面等离子体波共振光谱发生偏移, 且随着膜厚增加而逐渐发生红移; 当液体折射率n0处于1.333～1.388之间时, 蒸镀有Ta2O5薄膜的光纤表面等离子体波传感器波长灵敏度达到2235 nm/RIU(Refractive Index Unit); 通过在一支光纤探头上依次加工两个表面等离子体波传感区域, 实现了对光波信号的连续调制。