Visualization of Conformational Transitions of Artificial Polymeric Foldamers by AIEgen

Artificial foldamers have received much attention because they can be served as the ideal systems to simulate the bioactive secondary structures of biomacromolecules like nucleic acids and proteins. However, the conventional techniques to detect the conformational transitions in artificial foldamers are generally high cost, time-consuming, and trouble-some in sample preparation. Herein, we have demonstrated a simple, rapid, and efficient method for the visualization of solvent-driven conformational changes including helix transition and helix extension in a water-soluble poly(m-phenylene diethynylene)-based derivative using an aggregation-induced emission luminogen (AIEgen) as a visualizing agent. This method is relied on the fluorescence responses of the AIEgen to the varied local environments during the conformational transitions on the basis of the mechanism of restriction of intramolecular motions (RIM). The present study is crucial not only in facilitating our profound understanding of the changes in the secondary structures of biomacromolecules but also in widening the application of AIEgens as fluorescent probes.