Characterization of fusion protein monolayer properties With dual-gate graphene FETs

Biosensing devices based on graphene and nanostructures facilitate label-free detection with sensitivities beyond traditional methods. Specific biorecognition relies on selective immobilization of analytes in the close vicinity of the sensor surface. The sensitivity of the biosensor is defined by the height and polarizability of the dielectric layer that forms at the interface of graphene and the electrolyte and this layer is strongly modified by the protein structure. Even though liquid phase analysis is based on liquid gate, additional back gate under the sensing material increases the amount of information obtainable from the system. Unstability of the traditional gate dielectric, silicon dioxide, in electrolytes has turned the interest to high-k oxides. For example, HfO2 as gate dielectric reduces the gate leakage current when compared to SiO2.