Novel AIE-Active Polyarylethersulfone Polymers Incorporating Tetraphenylethene for Enhanced Fluorescence

Aggregation-induced emission (AIE) materials have gained significant attention for their unique fluorescence enhancement in the aggregated state. However, combining rigid polymers with AIE molecules to enhance luminescent properties remains to be investigated. In this work, two novel AIE-active polyarylethersulfone (PAES) derivatives are synthesized by incorporating tetraphenylethene (TPE) into either the side chain or main chain of PAES, resulting in side-chain polyarylethersulfone-tetraphenylethene (PAES-TPE) and main-chain polyarylethersulfone-tetraphenylethene (m-PAES-TPE), respectively. These derivatives are designed to investigate the influence of the rigid polymer backbone on the AIE properties of TPE. The incorporation of TPE into PAES resulted in a notable redshift in fluorescence emission compared to pure TPE. Notably, m-PAES-TPE_50%, a polymer with 50% molar content of TPE, exhibited a fluorescence quantum yield to 57.43%, more than twice that of TPE powder. Thermal analysis showed that both PAES-TPE and m-PAES-TPE have excellent thermal stability and temperature-dependent fluorescence. Additionally, these materials are processed into hydrophobic nanoparticles, and in vitro experiments demonstrated good fluorescence properties and biocompatibility for cancer cell bioimaging. This work highlights the potential of rigid AIE-active PAES derivatives for advanced bioimaging applications.