Chiral supramolecular hydrogel with controllable phase transition behavior for stereospeci fi c molecular recognition

摘要

Chirality is a basic characteristic in living systems, and therefore stereospecific molecular recognition remains a great challenge. Herein, we report on the enantioselective recognition of tryptophan (Trp) isomers with a chiral supramolecular hydrogel (CSH). The CSH can undergo reversible gel-so l transition at varying temperatures and pH values, resulting in significant changes in its morphologies and discernible differences in UV spectra and electrochemical properties. Next, the CSH gel (CSH-G) and the CSH sol (CSH-S) are used for the stereospecific molecular recognition of Trp isomers, and the CSH-G exhibits higher recognition capability due to its unique three-dimensional (3D) network framework. In addition, the CSH based enantioselective recognition is both temperatureand pH-sensitive, which could be ascribed to the gel-sol transition behavior of the CSH at varying temperatures and pH values. Finally, the exact quantitative analysis of the Trp isomers in non-racemic solutions with the developed CSH-G is demonstrated.