A Coumarin-Based Fluorescent Probe for Ratiometric Monitoring of Hg2+ in Live Cells

A new ultrasensitive ratiometric fluorescent probe for the monitoring of mercury ions via specific mercury triggered desulfurization of dithioacetal has been judiciously developed. This probe (MS5) exhibits an efficient fluorescence and color response toward Hg2+ in aqueous solution. Its excellent selectivity, visible light emission (450-650 nm), low detection limit (similar to 0.81 ppb), and fast response kinetics (within 30 s) make it better than most reported ones. More importantly, this probe (MS5) has also been smoothly applied to ratiometrically imaging Hg2+ in live HeLa cells.