Co-assembly or self-sorting in supramolecular hydrogels? Nano-IR sheds light on tripeptide assemblies

Supramolecular hydrogels composed of self-assembling short peptides are gaining momentum for enzyme mimicry. In particular, multicomponent systems that feature similar peptides with a self-assembling motif (e.g., Phe-Phe) and catalytic residues (e.g., His, Asp) offer a convenient approach to organize in space functional residues that typically occur at enzymatic active sites. However, characterisation of these systems, and especially understanding whether the different peptides co-assemble or self-sort, is not trivial. In this work, we study two-component hydrogels composed of similar tripeptides and describe how nano-IR can reveal important details of their packing, thus demonstrating to be a useful technique to characterise multicomponent, nanostructured gels.