Ultrafast microwave-assisted multicomponent tandem polymerization for rapid fabrication of AIE-active fluorescent polymeric nanoparticles and their potential utilization for biological imaging

The fabrication and biomedical applications of fluorescent polymeric nanoparticles (FPNs) with aggregation-induced emission (AIE) feature has attracted the most intensive research interest since the first discovery of AIE phenomenon by Tang' group. Although great attention has been devoted to preparation of AIE-active FPNs, an efficient, facile and versatile strategy is still highly desirable to advance their biomedical applications. In this work, a one-pot microwave-assisted multicomponent tandem polymerization was proposed to fabricate AIE-active FPNs based on a microwave-assisted Kabachnik–Fields (KF) reaction, which involves the conjugation of aldehyde group containing polyethylene glycol (CHO-PEG-CHO) and amino-group terminating AIE dye (H 2 N-PhE-NH 2 ) using diethyl phosphate as the lock. The KF reaction can occur under rather facile and mild experimental conditions (e.g. absent of catalyst and solvents, air atmosphere) with the assistance of microwave irradiation in 5   min. The resultant (PEG-DP-PhE) copolymers would self-assemble into FPNs that showed high water dispersibility and enhanced fluorescence intensity. The desirable cytocompatibility and cell uptake efficiency of PEG-DP-PhE FPNs endow their great potential for biomedical applications. Considering the convenience and effectiveness, the method should be promising for fabrication of many AIE-active functional materials with great application potential.