7-(2,4-Dinitrophenoxy)-4-methyl-2H-chromen-2-one

A turn-on fluorescent probe for hydrogen sulfide; ex/em = 323/445 nm, respectively, in DMSO and fluorescence intensity increases in the presence of sulfur-containing molecules; selective for sulfur-containing molecules, including cysteine, GSH, homocysteine, and selenocysteine; not cytotoxic up to a concentration of 150 µg/ml