Chiral Supramolecular Polymers Assembled by Amphiphilic Oligopeptide-Perylene Diimides and High Electrochemical Sensing

Various secondary structures, for example, β-sheet hydrogen bonds formed by oligopeptides exhibiting high directionality and selectivity provide a new avenue to regulate optoelectronic performances of supramolecular assemblies constructed by π-conjugated chromophores. In this work, oligopeptide-perylene diimides (AUPDIs) are synthesized to generate β-sheet strands which guide the formation of chiral supramolecular polymers with a diversity of morphologies in combination with the π-π stacking even in aqueous media. Complex morphology transitions are successfully controlled by simply adjusting the water volume fraction in the binary solvent of water and tetrahydrofuran from spherical hollow aggregates to long helical nanowires and to short nanofibers. The mechanism of the assembly changes from cooperative to the isodesmic model relying on AUPDI concentrations. This originates from the transformation in the β-sheet that regulates profoundly the arrangement of the AUPDI molecules. Prominently efficient and positive electronic sensing to triethylamine for highly helical nanowires engenders due to the highly ordered helical arrangement within the nanowires, fourfold of the short nanofibers.