Biocatalytic amide condensation and gelation controlled by light

We report on a supramolecular self-assembly system that displays coupled light switching, biocatalytic condensation/hydrolysis and gelation. The equilibrium state of this system can be regulated by light, favouring in situ formation, by protease catalysed peptide synthesis, of self-assembling trans-Azo-YF-NH2 in ambient light; however, irradiation with UV light gives rise to the cis-isomer, which readily hydrolyzes to its amino acid derivatives (cis-Azo-Y + F-NH2) with consequent gel dissolution.