Self-Assembled Ru(II)-Coumarin Complexes for Selective Cell Membrane Imaging

The cell membrane, as the protecting frontier of cells, is closely related to crucial biological behaviors including cell growth, death, and division. Lots of fluorescent probes have been fabricated to monitor cell membranes due to their simplicity and intuitiveness. However, the efficiency of those traditional probes has been limited by their susceptibility to photobleaching and poor water solubility. In this study, we have reported Ru(II)-coumarin complexes consisting of ruthenium, 1,10-phenanthroline, and coumarin 6 to further form self-assembled nanoprobes, for cell membrane targeting and imaging. The fluorescent property could be switchable from red to green through the dynamic disassembly of nanoprobes. Compared with commercial Dil, biocompatible nanoprobes exhibited superior stability for long-term cell imaging, along with remarkedly reduced background interference. Therefore, our self-assembled nanoprobe provides a powerful solution for investigating lipid trafficking with optical imaging.