Kinetic Evolution in Metal-Dependent Self-Assembly of Peptide-Terpyridine Conjugates

Nature realizes impressive structures and emergent functions through precisely organized non-covalent interactions, and this inspires the use of supramolecular motifs to engineer new materials. Herein, an amphiphilic peptide-terpyridine conjugate is reported that forms 1D nanostructures leading to hydrogels. Upon the addition of metal, a slow kinetic transition occurs, resulting in nanostructures which are dictated by the chosen metal binding to the terpyridine ligand. As such, bis-complex formation between terminal terpyridines redirects the assembly from peptide-driven 1D structures to an assortment of new nanostructures which evolve and appear over the course of weeks. Studies where pre-existing peptide structures are disrupted prior to metal addition yield these same structures right away, further confirming the kinetically labored pathway to their formation when beginning from an assembled state.