Aluminum and phosphorene based ultrasensitive SPR biosensor

Abstract In order to designing an ultrasensitive biosensor with high detection accuracy, a bimetallic (Al/Au) structure is proposed. Further sensitivity enhancement is obtained by applying Si nanosheet and some 2D materials. Few-layer phosphorene, graphene and tungsten disulfide are selected to enhance the angular sensitivity of the biosensor. Different coupling prisms are examined due to obtaining the best response. Considering the achievable highest sensitivity together with smallest minimum reflectance values, the optimized number of layers for each material is selected. Finally, 258% sensitivity enhancement with 3 nm Au, 7 nm Si and 5 layers of phosphorene on Al surface is obtained compared with bare Al-based SPR biosensor.