Design Of Angle Modulated Surface Plasmon Resonance Spectrometer

As an emerging biosensing technology, Surface Plasmon Resonance (SPR) technique, characterized by high sensitivity, label-free detection and real-time monitoring, has been extensively applied in biochemical analysis, environmental monitoring and refractive index measurement.In this study, according the modeling and simulation for the Surface Plasmon Resonance, several key parameters such as the light source, prism material, the thickness of golden film and Cr film has been determined. Then, an angle modulated surface plasmon resonance spectrometer system based on5-layer Kretchmann prism structure has been developed for biochemical analysis. The system is composed of hardware part and software part. The hardware part includes He-Ne laser, two coaxial stages, photoelectric detector, chopper and lock-in amplifier. And the sapphire prism, sensor chip and mechanical structure of the sampling system are designed all by ourselves. At the same time, the software program based on LabVIEW is designed for controlling the stages and data acquisition.System performance should be tested after the SPR system established. We test the power stability of the laser first, which is up to1.504%(5min). Different concentrations of glycerol are measured to demarcate the system. And then, using the system for deionized water ten-time continuous measurement, we use the standard deviation of the ten resonance angles to compute system detection sensitivity, which is up to1x10-5RIU. At last, different concentrations of glucose solution are measured, and the resonance angles are used to calculate the refractive index of the glucose solutions, which is more accurate than the result of Abbe refractometer. The relationship between concentration and refractive index is presented by liner fitting.