Design and Simulation of Au/SiO(2) Nanospheres Based on SPR Refractive Index Sensor

In this paper, three different structures of surface plasmon resonance (SPR) sensors based on the Kretschmann configuration: Au/SiO(2) thin film structure, Au/SiO(2) nanospheres and Au/SiO(2) nanorods are designed by adding three different forms of SiO(2) materials behind the gold film of conventional Au-based SPR sensors. The effects of SiO(2) shapes on the SPR sensor are investigated through modeling and simulation with the refractive index of the media to be measured ranging from 1.330 to 1.365. The results show that the sensitivity of Au/SiO(2) nanospheres could be as high as 2875.4 nm/RIU, which is 25.96% higher than that of the sensor with a gold array. More interestingly, the increase in sensor sensitivity is attributed to the change in SiO(2) material morphology. Therefore, this paper mainly explores the influence of the shape of the sensor-sensitizing material on the performance of the sensor.