(593b) Defect-Free Functionalization of Graphene for Building Ultrasensitive Graphene Biochemical Sensors

In this talk, we will present novel routes to functionalize the surface of pristine graphene with a single layer of biological molecules by employing the inter-mediatory non-covalent π-π stacking forces. The resultant graphene-biohybrid is leveraged as an electro-chemical transistor for sensitively probing its interaction with nano/micro scale biological derivatives. The current surface modification schemes introduce several defects in graphene as they can not retain, (a) the sp^2 hybridized state of C atoms (that decreases the high carrier density in the functionalized graphene), and (b) the planar graphene lattice (that introduces scattering sites on graphene lower the carrier mobility). We utilize the high density of π electrons on the surface of graphene for a multipoint π-π functionalization with physical/biological molecules without compromising the native integrity of its lattice. The π?functionalized graphene sheets (PFGs) are extensively characterized for their interfacial energies with stacked molecules, band-gap, density and mobility of charge-carriers and their selectivity & sensitivity for recognizing biomolecular derivatives. We envision that by utilizing the π-π chemistry on graphene, a novel class of defect free graphene-hybrids can be fabricated with enhanced potential for bio-chemical sensing and nanoelectronics.