Two birds one stone: facile preparation of AIE-active fluorescent polymeric nanoparticles via self-catalyzed photo-mediated polymerization

Abstract In this work, we report the first preparation of AIE-active FPNs via metal-free photo-mediated atom transfer radical polymerization (ATRP), employing 2-methacryloyloxyethyl phosphorylcholine (MPC) and benzyl methacrylate (BzMA) as the monomers. Herein, the AIE fluorogen, 10-phenylphenothiazine (PTH)-containing α-bromoester (named as PTH-Br), was simultaneously used as the initiator and photocatalyst. We found that the AIE-active PTH-P(BzMA-MPC)-20(40) FPNs in water can emit intense fluorescence, with high fluorescence quantum yields of 34.3% and 41.2%, respectively, and show excellent water dispersibility and a low critical micelle concentration (CMC). To explore their potential for biomedical applications, biocompatibility evaluation and the cell uptake behavior of these FPNs were further studied. The results demonstrated that these polymeric nanoparticles are biocompatible with L02 cells and are promising for bioimaging applications. Compared with the traditional strategies for preparing AIE-active FPNs, the method described in this work can occur at room temperature, does not require metal catalysts, and is highly efficient. This work lays the foundation for the fabrication of AIE-active functional materials and broadens the potential of AIE-active molecules.