Theoretical modelling of surface plasmon resonance biosensor employing graphene and SnSe heterostructure for Pseudomonas-like bacteria detection

In this study, using graphene with the addition layer coating of ɑ-SnSe as a two-dimensional(۲D) material, a novel SPR biosensor is proposed computationally for Pseudomonas-like bacterialdetection. The performance parameters like sensitivity and detection accuracy are calculated using theFrensel equation and transfer matrix method.For investigating the presence effect of ɑ-SnSe monolayer on the sensitivity improvement, theperformance of conventional structure consists of BK۷ prism, silver (Ag) thin film, graphenemonolayer, three affinity layers (toluene, poly (trifluoroethyl methacrylate) and nicotine) and sensingmedium has been compared with the proposed structure, BK۷/ Ag/ graphene/ ɑ-SnSe monolayer/affinity and sensing medium. The thickness of metal layer Ag and graphene are ۵۰ nm and ۰.۳۴ nm,respectively [۱]. Moreover, the SnSe is employed with an optimized thickness of ۰.۵۷۵ nm and affinitylayers with thickness of ۳ nm [۲,۳]. According to the results, the performance advancement of SPRbiosensor is observed by covering the graphene with ɑ-SnSe single layer. The biosensor yields themaximum sensitivity value of ۱۶۵.۸۵ deg/RIU and detection accuracy equal to ۱.۸۲ deg-۱ while therefractive index (RI) of sensing medium varies between ۱.۳۳ to ۱.۴۰ and for the affinity layer,toluene,with RI of ۱.۴۹۳۶۸. Considering the performance of the proposed structure, we believe that the inclusionof graphene with the ɑ-SnSe monolayer can find potential use in Pseudomonas and Pseudomonas-likebacteria detection for medical and biological detection applications.

کلیدواژه ها:

SPR Biosensor ، Pseudomonas bacteria ، Modeling ، Graphene ، SnSe