The development of effective strategies for fabrication of fluorescent organic nanoparticles (FONs) with an aggregation‐induced emission (AIE) feature has an important impact on the biomedical applications of these AIE‐active FONs. In the current work, an ultrafast strategy for fabricating AIE‐active FONs is developed through a “one‐pot” microwave‐assisted, catalysts‐free, and solvent‐free Kabachnik–Fields (KF) reaction for the first time. It is demonstrated that such organophosphorous‐containing AIE‐active block polymers can be synthesized within 2 min under air atmosphere through the microwave‐assisted KF reaction. These polymers show amphiphilic properties and can self‐assemble into mPEG‐CHO‐Phe‐NH2‐DEP FONs, which display high water dispersibility and desirable optical properties. Biological evaluation results suggest that the mPEG‐CHO‐Phe‐NH2‐DEP FONs exhibit low toxicity and are potential for biological imaging applications. More importantly, many other multifunctional AIE‐active FONs can also be fabricated through the strategy described in this work owing to the universality of KF reaction. Besides, combined with the excellent properties of mPEG‐CHO‐Phe‐NH2‐DEP FONs, it is believed that such microwave‐assisted KF reaction shall be an effective route for designing various AIE‐active nanomaterials for different biomedical applications.
