A novel reaction-based ratiometric fluorescent probe with large Stokes shift for the detection of Hg2+2+in river sample

Based on Hg2+-promoted 2 +-promoted desulfurization-hydrolysis of the diphenylphosphinothioate moiety, a novel ratiometric fluorescent probe 1 for Hg2+ 2 + using hemicyanine as the fluorophore was designed and synthesized. In sensing of Hg2+, 2 + , the maximum fluorescence emission and absorption peaks of 1 shifted from 450 nm to 504 nm and from 351 nm to 376 nm, respectively, accompanied by color change from colorless to green under illumination with a 365 nm UV lamp. 1 not only exhibited remarkable change in the ratios of both absorbance (A 376 nm/A351 /A 351 nm) ) and fluorescence intensity (F 504 nm/F450 /F 450 nm ), but also had large Stokes shift, fast response, excellent sensitivity, and high selectivity for Hg2+. 2 + . Furthermore, 1 was successfully applied for Hg2+ 2 + detection in river water sample.