Detection of biomolecule using Surface plasmon resonance sensor: Theoretical Analysis

In this study, we have designed a surface plasmon resonance (SPR) sensor using a graphene–MOS<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> layer along with the composite layer of Silver (Ag)-Nickle (Ni). Conventionally, we use angular interrogation for sensitivity enhancement. Here, we are using Ag and Ni along with the graphene and MOS<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> films the same used for Kretschmann configuration. We find that the suitable sensitivity of 229.75°/RIU, which can be realized with optimized thickness of Ag with 10nm thickness of Ni layer at graphene and MOS<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> layers. The maximal sensitivity of 240°/RIU is achieved at below 0.30 (a.u.) R<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">min</inf> value. The suggested sensor is suitable candidate for the detection of medical diagnosis between the range refractive index (RI) of 1.33-1.335.