4-methyl-7-[4-nitro-2-(trifluoromethyl)phenoxy]chromen-2-one

4-Methyl-7-(4-nitro-2-(trifluoromethyl)phenoxy)-2H-chromen-2-one is a turn-on fluorescent probe for the detection of hydrogen sulfide (H₂S). It can be excited at 348 nm in DMSO and fluorescence intensity increases in the presence of bisulfide (HS^-). 4-Methyl-7-(4-nitro-2-(trifluoromethyl)phenoxy)-2H-chromen-2-one is selective for HS^- over cysteine, AcO^-, F^-, H₂PO₄^-, Cl^-, Br^-, and I^- and is not cytotoxic up to a concentration of 150 μg/ml.

H2S Fluorescent probe 1 (Compound 2) is a fluorescent probe that detects hydrogen sulfide (H2S) with almost no cytotoxicity. Upon the addition of increasing amounts of HS- to DMSO solution of H2S Fluorescent probe 1, a new absorption peak appears gradually at 485 nm. H2S Fluorescent probe 1, the fluorescence intensity notes at 434 nm increasing rapidly by titration of HS-[1].

[1] Chen Y, et al. The synthesis, crystal, hydrogen sulfide detection and cell assement of novel chemsensors based on coumarin derivatives. Sci Rep. 2018 Nov 1;8(1):16159. DOI:10.1038/s41598-018-34331-9