Using multiple layers and surface roughness control for improving the sensitivity of SRP sensors

Abstract

Surface plasmon resonance (SPR) sensors have been developed quickly in the past twenty years in biosensing. However, the sensitivity of them restricts them from small molecular detection. This thesis focuses on the sensor chips of the SPR sensors and presents two potential methods to improve the sensitivity of currently used SPR sensor chips: the bimetallic layer sensor chip and surface roughness control of glass slide. The bimetallic layer sensor chip has been proved to produce better sensitivity performance than the currently used mono gold layer sensor chip by simulation because it takes the advantage of the good sensitivity performance that silver produces and protects silver from oxidizing by the outer gold layer. The surface of the glass slide, as a part of SPR sensor chip, is assumed to be planar in all the current research of SPR biosensors, which is not possible in real case. The surface roughness effect of the glass slide on the sensitivity of SPR sensor chip is investigated. Simulation has suggested that the improvement in the surface roughness of glass slide can enhance the sensitivity performance of SPR sensor chip. By controlling the surface roughness condition of glass slide through polishing, experiments shows that the sensitivity of SPR sensor chips is improved by making the surface of the glass slide smooth