Optimization of Surface Plasmon Resonance Sensor Based on Multilayer Film Structure

摘要

A prism-excited multilayer film Surface Plasmon Resonance(SPR)sensing structure of graphene-silver-graphenemeasured mediums is proposed to solve the unstablility and oxidization problem of metallic silver films for SPR sensors.By adding a graphene layer,the poor stability and the oxidization problem of silver film are solved.The electromagnetic field and reflection mechanism of the multilayer film structure are theoretically analyzed.The characteristics of the different metal materials for SPR,the distinct silver film thickness,and different graphene layers are studied through experiments to optimize the sensor design.Compared with the gold film sensor,the sensitivity of the multilayer film sensor with graphene layer is improved.The designed SPR sensor is used to detect a sucrose solution with a concentration of 0%-64%,and its refractive index is 1.33 to 1.45,linear correlation coefficient is 0.9984.Good resonance effect and sensing characteristics are thus obtained.