Graphene-based FET structure: Modeling FET characteristics for an aptamer-based analyte sensor

Graphene is a very promising electronic material that has attracted vast research interests due to its unique electronic properties [1]. In this paper, a graphene-based FET-like aptamer sensor is modelled for the case of an aptamer that binds to a cocaine surrogate. Methylene-blue (MB) is a nanoscale molecule that functions as an electron donor. The graphene in these structures exhibits p-type semiconductor behavior with holes as carriers. The voltage shift caused by electron trapping on the graphene surface is observed and explained by a charge sheet capacitance model. In this work, the graphene-based FET characteristics are modelled to understand the use of this device as a sensor of molecular analytes.