Sensitivity enhancement of SPR optical biosensor based on Graphene–MoS2 structure with nanocomposite layer

Abstract

The optical plasmonic biosensors are an important research item in the field of bio-photonics. The graphene-molybdenum disulfide (MoS2) based hybrid structures are very useful in designing and fabrication of the high sensitive biosensors. In this paper, we designed hetero-structured Air/MoS2/Nanocomposite/MoS2/Graphene as an optical biosensor with high sensitivity. The proposed configuration for this Surface Plasmon Resonance (SPR) biosensor is Otto configuration. Herein, the enhancement sensitivity of this proposed SPR biosensor is investigated in different arrangement of layers. The influence of the refractive index of the coupling prism, the thickness of the nanocomposite layer, the constituent components of the nanocomposite layer and the number of the MoS2 layer is investigated and the optimal values is calculated for the biosensor with maximum sensitivity. The maximum sensitivity ∼200°/RIU is achieved with six layers of MoS2 layer and a nanocomposite layer containing the gold nanoparticles and TiO2 as host dielectric.