Fano resonance in graphene-MoS2 heterostructure-based surface plasmon resonance biosensor and its potential applications

We propose a new configuration of surface plasmon resonance (SPR) sensor that is based on graphene-MoS2 hybrid structures for ultrasensitive detection of molecules. The present configuration is consisted of chalcogenide glass (2S2G) prism, Ag, coupling layer, guiding layer, graphene-MoS2 heterostructure and analyte. We perform numerical and analytical study of the impact of the thickness and refractive index (RI) of the coupling and guiding layer in a planar sensing structure within the Kretschmann configuration on the resonance properties of the excitation. Results of reflectivity calculations clearly demonstrate the sharp Fano-type resonance appears in the curve of SPR because of the coupling between surface plasmon polariton (SPP) and planar waveguide (PWG) modes. The properties of the Fano resonance (FR) strongly depend on the parameters of the structure. The calculated magnetic field profiles manifest that the hybrid nature of the electromagnetic (EM) modes excited in the present structure. The proposed system displays an enhancement factor of sensitivity by intensity more than 2 × 103-fold when compared to the SPR sensing scheme.