Graphene Field-Effect Transistor-Based Biological Sensors

Chemical and biological sensors based on graphene field-effect transistors (FETs) were described. The transfer characteristics of the graphene FET were changed by the solution pH and the protein adsorption. Especially, the detection limit of the solution pH was 0.03, indicating the high sensitivity. In order to achieve the specific biomolecule sensing, aptamers were used as a receptor material. The aptamer was the single-stranded DNA binding to the specific molecules. The aptamer-modified graphene FET can detect only the target molecule while the graphene FET with the bare graphene channel detects all proteins with charges. These sensing results show that the graphene FET has high potential for the high sensitive biological sensors.