Directed self-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 this work, oligopeptide with defined flanking sequences was appended to $\pi $-conjugated units, thereby directing their assembly processes in a designed manner. By utilizing custom-designed microfluidic devices and controlled acid vapor diffusion, the self-assembly rate was directed and precisely tuned. Notably, the kinetics was found to play a key role in the morphology of self-assembled $\pi $-conjugated oligopeptides. The influence of flanking peptide sequences and $\pi $-conjugated core-core interactions on the self-assembly nanostructure was systematically investigated. Importantly, the electronic properties of the synthetic peptide assembly was explored by integration as the active layer of a field effect transistor. The presented study offers insights to the design and fabrication of supramolecular electronics.