Ultrafast fabrication of fluorescent organic nanoparticles with aggregation-induced emission feature through the microwave-assisted Biginelli reaction

Abstract

Because of its unique optical properties, the aggregation-induced emission (AIE) dye has attracted extensive attention for various applications. Especially, the utilization of AIE-active dyes for fabrication of fluorescent organic nanoparticles (FONs) has attracted the most research interest for biomedical applications. Therefore, the development of novel and effective strategies to design and prepare AIE-active FONs should be of great importance for the biomedical applications of AIE-active FONs. In this report, we reported an ultrafast strategy that based on the one-pot microwave-assisted Biginelli reaction for fabrication of AIE-active poly(AA-AEMA-TPE) copolymers, which use the 2-(methacryloyoxy) ethylacet, acrylic acid (AA) and 4′,4‴-(1,2-diphenylethene-1,2-diyl) bis([1,1′-biphenyl]-4-carbaldehyde) (TPE-CHO) as the substrates. The microwave-assisted Biginelli reaction is simple, efficient and atom-economical and can be accomplished within 3 min. Owing to their amphiphilicity, poly(AA-AEMA-TPE) copolymers will self-assemble into FONs with small size and high water dispersibility. The proton nuclear magnetic resonance (1H NMR) spectroscopy, UV-Vis spectrum and fluorescence spectrometer were used to characterize the resultant copolymers. We demonstrated that poly(AA-AEMA-TPE) FONs possess many excellent properties, such as high water dispersibility, intense fluorescence, obvious AIE feature and favorable biocompatibility. The above results suggest that poly(AA-AEMA-TPE) FONs are of great potential for fluorescent imaging. Moreover, the microwave-assisted Biginelli reaction can occur under a rather benign environment with high efficiency and good substrate adaptability. Therefore, we believe that the method developed in this work could greatly advance the applications of AIE-active functional materials.