A Water-Soluble Fluorescent Probe for the Selective Sensing of Ag and its Application in Imaging of Living Cells and Nematodes.

In this study, an imidazole-coumarin based fluorescent probe was developed for the selective and sensitive detection of Ag in aqueous solution. Using a combination of Job plot, NMR titrations, and DFT calculations, the binding properties between Ag and the probe were deeply investigated, and the results revealed a 1:1 binding stoichiometry between the probe and Ag with a binding constant of 1.02 × 10 M. The detection limit was found to be 150 nM, which satisfies the requirement for the quantitative detection of Ag in real water samples. Moreover, the new probe, Ic, was successfully applied to sense Ag in HeLa and HepG2 cells as well as in C. elegans, indicating that it could be a useful tool for the environmental monitoring of Ag pollution. These results demonstrated that Ic could serve as a high-efficiency and low-cost fluorescent probe for tracking Ag in an aquatic environment and biological organisms.