Engineering Robust Supramolecular Nanoassemblies from Amino-Acid Functionalized Stiff-Stilbene Amphiphiles.

The unique functional properties and remarkable structural stability of proteins under extreme environments and conditions are largely predetermined by their constituent amino acid groups. However, the specific influence of molecular interactions arising from individual amino acids on overall structural stability of the resulting nanostructures remains insufficiently explored. Herein, we report a newly designed stiff-stilbene amphiphile functionalized with alanine amino acid groups (SA Ala ). The molecular design of SA Ala incorporates advanced π-π interactions between stiff-stilbene cores and amide hydrogen bonding, which together dictate the intermolecular distance and enable the construction of supramolecular nanostructures with pH and thermal stability at temperature up to 95°C. X-ray diffraction studies of the macroscopic soft scaffold of SA Ala further reveal that the presence of higher order tubular packing within the nanotubes of SA Ala serves as one of the crucial factors in extraordinary stability against structural deformation by external stimulations. Modifications on the steric bulkiness of the amino-acid side chain from methyl-groups to isopropyl-groups can reduce the structural stability of the corresponding nanostructures and macroscopic soft scaffolds stabilities towards light stimulations at macroscopic level. Combined with the demonstrated biocompatibility of SA Ala , these findings pave the way for the next generation design of biocompatible robust supramolecular materials.