▎ 摘　　要

Surface plasmon resonance based affinity biosensor comprising of 2S2G (Ge20Ga5Sb10S65) chalcogenide prism, graphene-multilayer and gold as a plasmon active metal is proposed for sensing over a broad wavelength range in visible and near infrared regime. We have investigated and carried out detailed analysis to design high performance affinity biosensor by exploiting the unique optical properties of chalcogenide glass and graphene. The performance of the biosensor has been quantified in terms of sensitivity and detection accuracy. The sensitivity of proposed biosensor increases significantly due to the presence of graphene where as the detection accuracy increases by more than 100% because of high index chalcogenide glass as compared to silica glass. Also, the detection accuracy of the proposed sensor in near IR is 16 times more as compared to that in visible. Adequate values of crucial design parameters have been optimized to achieve the best possible sensing performance over a broad wavelength range. (C) 2012 Elsevier B.V. All rights reserved.