Modeling of a fiber-optic surface plasmon resonance biosensor employing phosphorene for sensing applications

An enhanced optical fiber-based surface plasmon resonance (SPR) biosensor is proposed utilizing a two-dimensional phosphorene heterostructure as an interacting layer with the analyte. This is the first model so far of a phosphorene-based fiber-optic SPR biosensor. High sensitivity and figure of merit (FOM), the two desirable parameters, are analyzed to investigate sensor performance. The analysis indicates that the proposed sensor provides significantly higher sensitivity in comparison to conventional fiber-optic SPR sensors. Numerical study shows that on using 10 layers of phosphorene on the Ag layer, the fiber-optic biosensor exhibits extremely high sensitivity of 3725 nm/RIU with a FOM of 61 RIU-1. FOM reaches its maximum value of 64 RIU-1 with six layers of phosphorene. Effects of the number of heterostructure layers and light wavelength on sensitivity are also analyzed. The results will open a new way for using phosphorene heterostructure in an optical fiber-based SPR sensor for biosensing applications. (C) 2019 Society of Photo-Optical Instrumentation Engineers (SPIE)