A new fluorescent turn-on chemodosimeter for mercury ions in solution and its application in cells and organisms.

Using the Hg(2+)-induced desulfurization reaction of thiosemicarbazide derivative, we designed and synthesized a novel "turn on" coumarin-based fluorescent probe L with a simple structure for detecting mercury ion (II). Spectroscopy revealed that the probe responds selectively to mercury ions over other metal ions with marked fluorescence enhancement. Detection of Hg(2+) was effective at pH 7.0-9.5, with high selectivity and significant effect in HeLa cells, human umbilical vein endothelial cells and Escherichia coli, but no cytotoxicity. This probe could be an ideal and practical Hg(2+) probe with important biological significance.