Sensitivity Enhancement of Graphene-Based Surface Plasmon Resonance Biosensor Using Germanium Nanowires Grating

In this study we proposed a new surface plasmon resonance (SPR) configuration for enhancement of biosensor sensitivity with high absorbing molecules on the sensor surface. The proposed SPR structure consists of a germanium nanowires grating coated with three graphene layers while the addition of titanium layer between gold and fused silica (substrate) prevents the gold oxidation. For transverse magnetic (TM) mode, the changes in the electric and magnetic fields are presented. As a result of numerical study, the reflection and transmission characteristics of the SPR sensor are shown. The new structure increases 60% more resolution of SPR angle in compared to the known graphene-based SPR structure. Therefore, the proposed SPR configuration could potentially open a new possibility of graphene-based SPR for sensitivity and high throughput assessment of multiple biomolecular interactions.