Highly differentiated multi-stimuli-responsive fluorescence performance of tetraphenylethylene-containing styrene–maleic acid copolymers induced by macromolecular architecture control

Abstract

Stimuli-responsive aggregation-induced emission (AIE) active polymers with structural diversity and tunability in fluorescence responsive behavior are in high demand in practical applications. Recently, tetraphenylethylene (TPE)-appended maleic anhydride terpolymers were proposed as a multi-stimuli-responsive fluorescence platform by our group. Here, we report TPE-containing styrene–maleic acid copolymers with diverse chain topologies and locations of the TPE moiety by reversible activation-fragmentation transfer polymerization (RAFT) with meticulously designed chain transfer agents and a TPE-containing monomer. The fluorescence responsiveness of the copolymers to the pH value, Ca²⁺, and bovine serum albumin (BSA) was systematically investigated, which showed an influence substantially on both the “stimuli acceptor” and “signaling” sides of the macromolecular structure. The discovery made in our work accentuates the importance of macromolecular engineering in developing fluorescent probes with highly differentiated performance and provides great flexibility in meeting the wide range of requirements of various applications.