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.