Black phosphorus mediated long-range SPR imaging sensor with ultrahigh imaging sensitivity, penetration depth and figure of merit

Abstract

In this paper, we proposed a black phosphorus (BP) mediated long-range surface plasmon resonance (LRSPR) imaging sensor (Structure: 2S2G prism/Teflon/Ag/BP/Sensing medium) for refractive index (RI) sensing. MATLAB and COMSOL simulation software is used for analytical analysis of the proposed design at 633 nm characteristic wavelength. Use of Teflon dielectric buffer layer (DBL) and thin Ag film generates long-range surface plasmon polaritons (LRSPPs) at both interface of Ag film. BP layer is used as biorecognition element (BRE) layer for attachment of analytes due to its unique electrical, optical and electronic properties useful for sensing applications. The proposed sensor demonstrates maximum imaging sensitivity (29,971 RIU−1), detection accuracy (111 Deg.−1), angular figure of merit, FoMang. (2568 RIU−1), imaging figure of merit, FoMimg (810,027 RIU−1) and penetration depth, PD (1957 nm). Ultrahigh imaging sensitivity, FoMimg and micron size PD of the proposed sensor can be efficiently utilized for the deep analytes sensing even in smaller concentrations. Thus, BP mediated proposed RI sensor could provide potential application for micron size biomolecule sensing.