Graphene-Based Field Effect Transistors for Use in Biodetection of Hemoglobin

Biosensors which utilize both well-known properties of optoelectronic devices and the vibrational fingerprints of biomolecules have been a promising avenue for detection and characterization of biomaterials. Graphene with outstanding properties has been used as an inorganic component and biomolecules of interest will excite resonantly in the graphene channel at particular wavelengths will generate an electrical signal. Hemoglobin as a measurable particle is of particular interest, as it has an absorbance spectrum in the visible range, meaning that it will readily create a large electrical signal when combined with graphene and illuminated with visible light. We have fabricated graphene field-effect transistor devices and use them to detect the concentration of hemoglobin in aqueous solutions. In these measurements, we have found that the electrical signal depends strongly on both the incident wavelength as well as the concentration of hemoglobin in solutions.