The preparation of organoboron-based stilbene nanoparticles for cell imaging.

In this work, a series of nanoparticles were prepared assembled by a highly emissive solid-state organoboron-based stilbene (OBS) and PS-PEG-COOH via regulating the ratio of these two compounds using a co-precipitation method. The resultant OBS nanoparticles (OBSNs) were homogeneously dispersed in water media with average sizes of 36-82 nm and exhibited large Stokes shift, high fluorescence quantum yield, excellent photostability and low cytotoxicity. These organic nanoparticles could be internalized by MCF-7 cells and could accumulate in the cytoplasm outside the organelles. In addition, it is found that the nanoparticles with least negative charge and moderate size are most easily internalized by cells. Furthermore, the internalized nanoparticles could be retained inside the live cells for a long time and could be uniformly separated into two cells after the cell division process, permitting long-term cellular imaging applications.