(556e) Colloidal Directed Assembly of Pi-Conjugated Oligopeptides for Supramolecular Electronics

The directed mesoscale engineering of nanoscale building blocks holds enormous promise to catalyze a revolution in new functional materials for advanced electronics. Bio-inspired systems can play a key role in this effort due to their inherent "programmable" function. In nature, biological polymers form chemically complex and functional heterostructures that underlie life processes. From this perspective, the ability to efficiently harness the assembly of synthetic peptides could offer effective pathways to produce functional materials. In this work, we study the self-assembly and directed assembly of non-natural peptides containing conjugated synthetic cores. In these materials, pi-conjugated units are flanked by symmetric oligopeptides with defined sequences, thereby yielding materials that can assemble into hierarchical structures via straightforward triggering with acidic solutions. We employ a general and facile strategy to induce self-assembly of synthetic peptides by simple evaporation of polar aprotic solvents. Notably, macroscopic peptide fiber arrays were crafted by confining the evaporation of peptide monomer solutions within preformed colloidal microchannels. Following assembly, we characterize the optical properties of peptide fiber arrays containing pi-conjugated cores using a variety of techniques. We further interrogate the electronic properties of these materials by integrating synthetic peptide assemblies as the active layer in a field-effect transistor (FET). In this way, the present study offers new insights into the design and fabrication of supramolecular electronics.