Fabrication of AIE-active fluorescent polymeric nanoparticles with red emission through a facile catalyst-free amino-yne click polymerization

Fluorescent polymeric nanoparticles (FPNs) as novel probes have attracted more and more attention for biomedical applications owing to their optical properties and multifunctional potential. However, most of FPNs based on conventional organic fluorogens encounter serious aggregation-caused quenching (ACQ) effect. In this work, to overcome these problems, amphiphilic fluorescent copolymers [Poly(PEGY-PhE)] containing aggregation-induced emission (AIE) fluorogens (AIEgens) have been prepared via a facile amino-yne click polymerization under rather mild experimental conditions (catalyst-free and room temperature). The Poly(PEGY-PhE) copolymers can self-assemble into FPNs and be well dispersed in aqueous solution. Fluorescence spectra demonstrate that Poly(PEGY-PhE) FPNs possess strong red fluorescence, excellent photostability and low critical micelle concentration. The biological assays confirm that these AIE-active Poly(PEGY-PhE) FPNs possess low cytotoxicity towards L929 cells and cell dyeing performance. More importantly, this amino-yne click polymerization provides a simple strategy to prepare robust biocompatible fluorescent nanoparticles for biological imaging because of their high efficiency, mild reaction conditions and simple experimental operation procedure.