Graphene and Beyond Graphene MoS2: A New Window in Surface-Plasmon-Resonance-Based Fiber Optic Sensing

We theoretically propose a surface-plasmon-based fiber optic biosensor in metal/graphene/MoS2 configuration with molybdenum disulfide (MoS2) as a bio recognition layer. The proposed configuration works in the visible region of the electromagnetic spectrum with a very high sensitivity. A comparative theoretical study of the sensors with different metallic layers of gold (Au), copper (Cu), and aluminum (Al) has been performed. The sensor has been found to be the most sensitive in both Cu/graphene/MoS2 and Al/graphene/MoS2 configurations with sensitivity of 6.2 mu m/RIU. In both of the configurations the thicknesses of Cu and Al layers is 50 nm and the number of layers of graphene is 16 and 27, respectively, while only a single layer of MoS2 has been used. The sensitivity of the sensor in the Au/graphene/MoS2 configuration is 5.0 mu m/RIU with comparatively high depth of resonance.