Graphene biosensor

Abstract

Since the electrical characteristics of graphene field-effect transistors (FETs) are very sensitive for their environmental condition, the graphene FETs have high potential for chemical and biological sensors. In this chapter, the electrical detection of biomolecules and ions by graphene FETs was described. The grapheme FETs can be operated in the buffer solution by top-gate operation from a reference electrode without any passivation film. And their transconductance was more than 200 times larger than that of the conventional back-gate operation in vacuum. The drain current increased with increasing the solution pH. And the grapheme FETs detected the charges in proteins. To detect the specific protein, aptamers were functionalized on the graphene surface. As results, aptamer-modified grapheme FETs detected the target molecule, and their sensitivity was comparable to other aptamer-based biosensors.