采用虚拟仪器技术的表面等离子体共振传感器

Surface plasmon resonance sensor with virtual instrument techniques

针对表面等离子体共振(SPR)传感器对精度和数据处理能力的要求,利用虚拟仪器技术,自行设计了一套基于角度扫描的Kretschmann结构SPR测试系统。为了提高折射率的测量分辨力,系统采用了高精度步进电机控制的旋转平台。软件中使用巴特沃思低通滤波器消除出射光干涉噪声引起的高频干扰。同时,提出了一种双棱镜自适应结构对出射光路进行实时调整,实现角度扫描过程中光探测器固定不动。实验测得空气和蒸馏水样品的折射率分别为1.00293和1.33432,结果与理论值基本吻合,且具有良好的重复性和达到10-5RIU(RefractiveIndexUnit)的分辨力。

To satisfy the need of precision and capability of data processing of a surface plasma resonance （SPR） sensor, a measurement system for SPR with Kretschmann configuration is designed based on angle-scanning and virtual instrumentation technology. In order to improve the metrical resolution of refractive index, a rotating stage with high-precision stepping motor is utilized in the system. To eliminate high-frequency disturbances caused by interference noise from output ray, a Butterworth low-pass filter is used in the so,ware. Meanwhile, a double-prism adaptive structure for real-time optical regulation of output ray is proposed for real time regulation of the output optical path so as making the photo-detector fixed during angle-scanning process. Refractive indexes of air and distilled water sample obtained from experiments are 1.00293 and 1.33432 respectively, which accord with theoretical values approximately with good repetition and resolution to 10^-5RIU （refractive index unit）.