One-step preparation of branched PEG functionalized AIE-active luminescent polymeric nanoprobes

The synthesis of amphiphilic aggregation-induced emission (AIE) dyes based organic nanoparticles has recently attracted increasing attention in the biomedical fields. These AIE dyes based nanoparticles could effectively overcome the aggregation caused quenching effect of conventional organic dyes, making them promising candidates for fabrication of ultrabright organic luminescent nanomaterials. In this work, AIE-active luminescent polymeric nanoparticles (4-NH 2 -PEG-TPE-E LPNs) were facilely fabricated through Michael addition reaction between tetraphenylethene acrylate (TPE-E) and 4-arm-poly(ethylene glycol)-amine (4-NH 2 -PEG) in rather mild ambient. The 4-NH 2 -PEG can not only endow these AIE-active LPNs good water dispersibility, but also provide functional groups for further conjugation reaction. The size, morphology and luminescent properties of 4-NH 2 -PEG-TPE-E LPNs were characterized by a series of techniques in detail. Results suggested that these AIE-active LPNs showed spherical morphology with diameter about 100–200 nm. The obtained 4-NH 2 -PEG-TPE-E LPNs display high water dispersibility and strong fluorescence intensity because of their self assembly and AIE properties of TPE-E. Biological evaluation results demonstrated that 4-NH 2 -PEG-TPE-E LPNs showed negative toxicity toward cancer cells and good fluorescent imaging performance. All of these features make 4-NH 2 -PEG-TPE-E LPNs promising candidates for biological imaging and therapeutic applications.