Highly sensitive graphene biosensors based on surface plasmon resonance

TLDR

A graphene sheet coated above a gold thin film, previously proposed and experimentally fabricated, serves as the basis for the sensor. The study presents a surface plasmon resonance (SPR) based graphene biosensor. The biosensor employs attenuated total reflection (ATR) to detect refractive index changes caused by biomolecule adsorption at the sensor surface. The graphene‑on‑gold SPR biosensor is (1 + 0.025 L) × γ times more sensitive than a conventional gold thin‑film SPR biosensor, due to increased biomolecule adsorption and graphene’s optical properties.

Abstract

A surface plasmon resonance (SPR) based graphene biosensor is presented. It consists of a graphene sheet coated above a gold thin film, which has been proposed and experimentally fabricated recently [ChemPhysChem 11, 585 (2010)]. The biosensor uses attenuated total reflection (ATR) method to detect the refractive index change near the sensor surface, which is due to the adsorption of biomolecules. Our calculations show that the proposed graphene-on-gold SPR biosensor (with L graphene layers) is (1 + 0.025 L) x gamma (where gamma > 1) times more sensitive than the conventional gold thin film SPR biosensor. The improved sensitivity is due to increased adsorption of biomolecules on graphene (represented by the factor gamma) and the optical property of graphene.