Long-Range Surface Plasmon With Graphene for Enhancing the Sensitivity and Detection Accuracy of Biosensor

A novel long-range surface plasmon with graphene is proposed to enhance the sensitivity and detection accuracy (DA) of the biosensor. Compared with the conventional long-range surface plasmon resonance (LRSPR) structure with Au, the coating of the metal surface with graphene is employed to increase the biomolecules adsorption, prevent oxidation, and enhance the sensitivity and DA. Furthermore, we demonstrated that the sensitivity has a nearly tenfold improvement with a huge increasing DA in the proposed LRSPR biosensor compared with the SPR biosensor. Finally, we discuss the influence of the refractive index of sensing medium on the LRSPR biosensor and find that the sensitivity is changing with the refractive index of the sensing medium and that an optimal sensitivity can be obtained at a suitable refractive index. We believe that this scheme could find potential applications in chemical examination, medical diagnosis, and biological detection.