A comparative study of different types of sandwiched structures of SPR biosensor for sensitive detection of ssDNA

Graphene and other 2D materials have attracted many scientific communities due to excellent performance in the area of SPR biosensor. In this paper, we propose SPR biosensors for the detection of ssDNA using hybrid structure of different 2D materials in Kretschmann configuration. Further, we compare eight different types of configurations using silver (Ag), graphene, gold (Au) and transition metal dichalcogenides (TMDCs) in terms of various sensing performance parameters such as sensitivity (S), detection accuracy (D. A) and quality factor (Q. F). The schematic study of different configurations indicates that introduction of graphene, WS2 and MoS2 increase the sensing performances as compare to the conventional SPR biosensor. In our proposed structures, maximum sensitivity occurs for monolayer graphene, bilayer WS2 and monolayer MoS2 combination. In this case, maximum obtained sensitivity is 203 deg./RIU with detection accuracy 1.13 and quality factor 28.31 RIU-1. This analysis shows that heterostructure SPR biosensor with sandwiched graphene layer, consisting of bimetallic layers of TMDCs, enhances the sensing performance as compare to the other reported works which comprised of graphene and 2D materials. Therefore, our proposed SPR biosensor may have potential applications in medical diagnostic for biochemical detection and open a new dimension in the field of biosensing.