Multilayer Nano-Structure for Enhanced Sensitivity of Surface Plasmon Resonance Biosensor

Abstract

In this work, we demonstrated the figure of merits (FOM) of the plasmonic refractive index sensor using prism based on surface plasmon resonance (SPR). The multilayer structure comprising of the stacked layers of prism/TiO2/Ag/MoS2 with an operating wavelength of near-infrared region used for SPR excitation. It is reported that the optical reflectance spectrum of the SPR sensor can be easily tuned by changing the thicknesses of TiO2, Ag and MoS2 layers. With the optimized thicknesses of the TiO2, Ag and MoS2 layers at 180, 35 and 5 nm, respectively, the findings show that the SPR sensor was obtained at about 102/RIU, which corresponds to a sensor sensitivity of 96.28 º/RIU. This refractive index sensor shows the great sensitivity and detection accuracy by enabling biochemical detection utilizing a small volume of liquid for biological diagnosis.