Investigations on sensitivity enhancement of SPR biosensor using tunable wavelength and graphene layers

Abstract

Surface plasmon resonance (SPR) is a well-known, rapid and sensitive technique used for probing the biomolecular interactions in real time. Several new approaches have been suggested to improve the sensitivity of SPR sensors over the last two decades. Recently, there have been few reports on using graphene on a metal film based SPR sensor in order to improve the sensitivity. The role of incident light wavelength and graphene layers in sensitivity enhancement is unclear. This paper reports computational investigations on sensitivity enhancement of SPR biosensor using tunable wavelength and graphene layers. The reflectivity of p-polarized incident light has been calculated using the N-layer model for the most common Kretschmann configuration. Sensitivity enhancements over a conventional angular interrogated SPR sensor have been calculated within the wavelength range 600 -1600 nm and up to ten graphene layers. Results indicate that the sensitivity can be enhanced by the increasing the graphene layers on conventional gold coating based SPR biosensor. Sensitivity enhancement is highly dominated by the wavelength of interrogation used in this design. By tuning the wavelength and graphene layers sensitivity of the graphene-based SPR biosensor can be increased.