Selective Coassembly of Aromatic Amino Acids to Fabricate Hydrogels with Light Irradiation-Induced Emission for Fluorescent Imprint

Adv Mater. 2018 Feb;30(5). doi: 10.1002/adma.201705633. Epub 2017 Dec 11.

Abstract

Controlling the structural parameters in coassembly is crucial for the fabrication of multicomponent functional materials. Here a proof-of-concept study is presented to reveal the α-substituent effect of aromatic amino acids on their selective coassembly with bipyridine binders. With the assistance of X-ray scattering technique, it is found that individual packing in the solid state as well as bulky effect brought by α-substitution determines the occurrence of coassembly. A well-performed hydrogels based on the complexation between certain aromatic amino acids and bipyridine units are successfully constructed, providing unprecedented smart materials with light irradiation-triggered luminescence. Such hydrogels without the phase separation and photobleaching during light irradiation are able to behave fluorescent imprint materials. This study provides a suitable protocol in rationally designing amino acid residues of short peptides for fabricating self-assembled multicomponent materials. In addition, this protocol is useful in screening potential functional materials on account of diverse self-assembly behavior.

Keywords: aromatic amino acids; coassembly; fluorescent imprinting; photoresponsive emission; supramolecular complexations.