Chemical functionalization of graphene enabled by phage displayed peptides

The development of a general approach for the nondestructive chemical and biological functionalization of graphene could expand opportunities for graphene in both fundamental studies and a variety of device platforms. Graphene is a delicate single-layer, two-dimensional network of carbon atoms whose properties can be affected by covalent modification. One method for functionalizing materials without fundamentally changing their inherent structure is using biorecognition moieties. In particular, oligopeptides are molecules containing a broad chemical diversity that can be achieved within a relatively compact size. Phage display is a dominant method for identifying peptides that possess enhanced selectivity toward a particular target. Here, we demonstrate a powerful yet benign approach for chemical functionalization of graphene via comprehensively screened phage displayed peptides. Our results show that graphene can be selectively recognized even in nanometer-defined strips. Further, modification of graphene with bifunctional peptides reveals both the ability to impart selective recognition of gold nanoparticles and the development of an ultrasensitive graphene-based TNT sensor. We anticipate that these results could open exciting opportunities in the use of graphene in fundamental biochemical recognition studies, as well as applications ranging from sensors to energy storage devices.