Layered transition metal dichalcogenides (TMDCs) within two dimension (2D) have been gaining widespread consideration due to their exclusive optoelectronic properties. Here, we propose a hybrid nanostructured plasmonic biosensor composed of layered materials (TMDCs and graphene) on a Au film intended for increasing the Goos–Hänchen (GH) shift of the reflected light. MoS2 and WS2 are chosen as the TMDCs to constitute the sensing materials. We provide a detailed simulation and theoretical analysis of the performance of the sensor based on surface plasmon resonance (SPR) composed of the proposed hybrid nanostructure for wavelengths spanning from the visible to near-IR spectral region. The sensing performance is evaluated in terms of sensitivity, figure of merit (FoM), and enhancement factor. Four optimal configurations are achieved at different excitation wavelengths, where the largest enhancement factor of sensitivity is over five times in comparison to conventional bare gold sensors. Also, the detection limit of the refractive index (RI) change is decreased by two orders of magnitude and its corresponding sensitivity shows over ten times improvement.
