Scalable Arrays of DNA-decorated Graphene Chemical Vapor Sensors

Chemical vapor sensors based on biomolecular functionalization of graphene field effect transistor arrays are demonstrated. Novel photolithographic methods were developed to fabricate high quality transistors from CVD-grown graphene. Atomic Force Microscopy was used to verify that the graphene surface remained uncontaminated and was thus suitable for controlled chemical functionalization. Single-stranded DNA was chosen as the functionalizing biomolecule due to its affinity to a wide range of target molecules as well as its $\pi $-$\pi $ stacking interaction with graphene, which allowed functionalization with minimal impact on the transistor mobility. The resulting sensor arrays showed analyte and DNA sequence dependent responses down to parts-per-billion level concentrations. By using large arrays of differently functionalized devices, we distinguished chemically similar analytes and determined electronic signatures indicative of their presence.