Sparks fly when AIE meets with polymers

Biological and synthetic polymers play important roles in human life and modern society. Understanding their properties and dynamic processes are thus particularly crucial. However, modern instruments suffer from ex situ, tedious sample preparation, and even show "blindness" to the testing process. Fortunately, fluorescent technology based on aggregation-induced emission (AIE) luminogens is cutting-edge and holds great potential to address this challenge. Owing to their twisted flexible structures, the emission of AIE luminogens (AIEgens) is sensitive to the surrounding microenvironmental changes, enabling them to function as sensitive fluorescent probes based on the mechanism of restriction of intramolecular motion (RIM). AIEgens can even detect subtle polarity variation when imparting them with donor-acceptor structures to trigger the twisted intramolecular charge transfer effect. In this short review, we have briefly described the recent applications of AIEgens in polymer-related fields for monitoring protein conformation, fibrillation, and enzyme activity, DNA synthesis, sequence and G-quadruplexes, analyzing a polymerization reaction, glass transition, and phase separation, and detecting humidity, and heat, etc. The outlook on the further applications of AIE technology in the polymer field is also discussed.