Self-assembled peptide nanowires on single-layer graphene and MoS$_{2}$ with biomolecular doping effect*

Developing elegant hybrid systems of biological molecules on atomic single layers (ASLs), such as graphene, is a key in creating novel bio-nanoelectronic devices, where versatile biological functions are integrated with electronics of ASLs. Biomolecules self-assembling into ordered structures on ASLs offer a novel bottom-up approach, where organized supramolecular architectures spatially govern the ASL electronics. Despite the potential in bridging nano- and bio-worlds at the molecular scale, no work has yet realized a way to control electronic and optical properties of ASLs by the biomolecular structures. Here, we demonstrate that engineered dodecapeptides self-assemble into supramolecular networks of peptide nanowires on single-layer graphene and MoS$_{2}$. Peptide nanowires introduce electric charge into these ASLs \textit{via} biomolecular doping. Abrupt boundaries of nanowires create electronic junctions in graphene, which manifest themselves within the single-layer as a self-assembled electronic network. Furthermore, the designed peptides modify both conductivity and photoluminescence of single-layer MoS$_{2}$. Controlling nano-electronics through engineered peptides potentially opens up new avenues in self-assembly of nanodevices for future bioelectronics.