A thiocoumarin-based colorimetric and ratiometric fluorescent probe for Hg2+ in aqueous solution and its application in live-cell imaging

A new intramolecular charge transfer (ICT) based colorimetric and ratiometric fluorescent chemodosimeter for the detection of Hg2+ has been rationally designed and developed. The probe operates via the specific mercury-promoted desulfurization reaction of thiocoumarin to coumarin and exhibits high selectivity and sensitivity in almost pure aqueous solution (containing only 1% DMSO) with a low detection limit of 1.85 ppb. Furthermore, the probe was successfully used for the fluorescence imaging of Hg2+ in live cells.