Facile fabrication of aggregation-induced emission based red fluorescent organic nanoparticles for cell imaging

A cyano-substituted diarylethlene derivative aggregation-induced emission (AIE) dye with two amino end-groups and 4,4'-(hexafluoroisopropylidene)diphthalic anhydride were facilely incorporated into red fluorescent organic nanoparticles (FONs) via room temperature anhydride ring-opening polymerization under an air atmosphere. These obtained RO-HFDA FONs were characterized by a series of techniques including gel permeation chromatography, Fourier transform infrared spectroscopy, size distribution and zeta potential measurements, UV-Vis absorption spectrum, fluorescent spectroscopy and transmission electron microscopy. Biocompatibility evaluation and cell uptake behavior of RO-HFDA FONs were further investigated to explore their potential biomedical application. We demonstrated that such FONs showed high water dispersibility, stable uniform spherical morphology (150-200 nm), broad excitation band (350-605 nm), intense red fluorescence (627 nm) and excellent biocompatibility, making them promising for cell imaging applications.