Development of a Nile-blue based chemodosimeter for Hg2+ in aqueous solution and its application in biological imaging.

A Nile blue-based chemodosimeter was newly synthesized. It can detect Hg(2+) in aqueous solution based on desulfurization reaction. Upon its addition into aqueous Hg(2+) ion solution, it exhibited a considerable blue-shift in its absorption and obvious fluorescence quenching. The detection mechanism was proved by mass spectrometry analysis and Gaussian calculations. Detection at an emission of 685 nm was extremely sensitive, with a detection limit of 2.5 × 10(-9) mol/L. The fluorescent images in living cells and zebrafish demonstrate its potential for studying the accumulation of mercury species in organism.