A Novel NIR Fluorescent Probe with Large Stokes Shift for the Detection of Hg2+ and its Imaging in Living Cells and Zebrafish.

Mercury (Hg) ranks among the most hazardous metals. Hg2+ contamination has grown to be a major concern for people worldwide. Thus, it is crucial to discover a quick, practical, and reliable method of Hg2+ testing for both human health and the ecological environment. In the present study, a NIR fluorescent probe TP-Hg was designed for Hg2+ detection based on thiopyran tetracarbonitrile by employing the Hg2+-triggered thioacetal deprotection reaction. Spectral experimental results demonstrated TP-Hg possessed excellent selectivity toward Hg2+ (λex/em = 563/770 nm), with good sensitivity (LOD = 0.13 µM) and high anti-interference performance. Bioimaging assays showed that the probe TP-Hg enabled accurate detection of Hg2+ in living cells and zebrafish. Moreover, this probe was successfully applied to detect Hg2+ on test strips.