Recognition of Thiols in Living Cells and Zebrafish Using an Imidazo[1,5-α]pyridine-Derivative Indicator

A new cyan fluorescent probe, MIPY-DNBS, using an imidazo[1,5-α]pyridine derivative as the fluorophore and 2,4-dinitrobenzensufonate as the recognition site for the selective detection of thiols (Cys, GSH, and Hcy), was designed and synthesized. Probe MIPY-DNBS exhibited a 172 nm Stokes shift, a fast response time (400 s), low cytotoxicity, low detection limits (12.7 nM for Cys), and excellent selectively in the detection of thiols. In addition, MIPY-DNBS was successfully applied to imaging thiols in living MCF-7 cells and zebrafish.