Photo-response of Photoreceptor Proteins Based on Graphene Field Effect Transistors

Based on the unique properties of graphene, efforts have been made to realize bioelectronic devices, which combine the biological functionalities of a biomolecule to an inorganic component. A detection method can be developed based on optical properties of biomolecules that generate electrical readout. Photoreceptor yellow protein is one kind of light-sensitive protein, which is activated by light and absorbs photons. We have fabricated graphene field-effect transistor (GFETs) devices for biomolecular detection of photoreceptor yellow proteins in the visible range. Experimentally, current-voltage measurement by tuning the gate voltage has been carried out to elucidate the electronic properties of GFETs based biosensors. The wavelength dependent photo-response due to the absorption spectrum of photoreceptor proteins has also been studied under varied illuminations. The device shows a strong photo-response for a low concentration solution of photoreceptor yellow protein.