Sensitivity enhancement of SPR biosensors employing heterostructure of PtSe2 and 2D materials

In this paper, two exclusive surface plasmon resonance (SPR) biosensors are proposed numerically utilizing the newly emerged transition metal dichalcogenides (e.g. PtSe2) composed with 2D materials (e.g. Graphene, MoS2 and WS2) onto the traditional SPR biosensors. The performance of the sensors is investigated using the technique of attenuated total reflection (ATR) in terms of sensitivity, figure of merit (FOM) and quality factor (QF). Among those sensors, it has been noticed that the Ag/PtSe2/WS2 and Au/PtSe2/WS2 structures, respectively, show very high sensitivity of 194 deg/RIU and 187 deg/RIU which are 1.67 and 1.37 times higher than that of the conventional silver (Ag) and gold (Au) based sensors, respectively, with comparable FOM and QF. The thickness of Ag/Au is considered 50 nm and the number of layers of WS2 is adjusted to 4 and 2 for Ag and Au based sensors, respectively. In both cases, an optimized thickness of 2 nm is used for PtSe2. Such impressive performances of the proposed biosensors will pave a way for their use in future medical diagnostics and biomedical detection applications.