The combination of controlled living polymerization and multicomponent reactions to prepare tetraphenylethylene-containing fluorescent block copolymers

Abstract

Abstract High-efficiency multicomponent reactions (MCRs) have received increasing attention and widely used to prepare functional materials because of many prominent advantages such as simple “one-pot” operation, clear product structure, atom economic and environmentally friendly. Combining conventional reversible addition-fragmentation chain-transfer (RAFT) polymerization and new MCRs to prepare multifunctional polymer nanomaterials should be an interesting research direction for polymer chemistry and materials science. In this research, aggregation-induced emission (AIE)-active fluorescent amphiphilic block copolymers were designed and prepared by the combination of reversible RAFT polymerization and mercaptoacetic acid locking imine (MALI) method. These amphiphilic block copolymers that contain the hydrophobic tetraphenylethylene (TPE) derivative and hydrophilic polyethylene glycol (PEG) could be self-assembled into structure with spherical morphology and small particle size. Owing to the aggregation of hydrophobic TPE derivative, these self-assembles display obvious AIE feature. On the other hand, thus-obtained fluorescent organic nanoparticles (FONs) could also be well dispersed in aqueous solution because of the existence of hydrophilic PEG. All the characterization results demonstrated that we could facilely synthesized these fluorescent amphiphiles through the strategy described above. The preliminary results from biological assays suggested that these AIE-active FONs are of low cytotoxicity and could be potentially used for living cell imaging. Taken together, we reported a one-pot strategy for synthesis of TPE-containing FONs through the combination of RAFT polymerization and MALI reaction for the first time. This strategy could also be extended for fabrication of many other functional composites owing to their unique features. We trust this work should be great advance the biomedical applications of AIE-active functional materials.