Reaction-based colorimetric and fluorogenic signaling of hydrogen sulfide using a 7-nitro-2,1,3-benzoxadiazole–coumarin conjugate

A novel reaction-based probe for the dual signaling of hydrogen sulfide (H2S) was investigated. The selective H2S-induced cleavage of the ether linkage of the 7-nitro-2,1,3-benzoxadiazole (NBD) and 7-hydroxycoumarin conjugate resulted in a dual signaling behavior. The colorimetric and fluorogenic signaling behaviors were attributed to the H2S-induced generation of 7-nitrobenzo-2,1,3-oxadiazole-4-thiol (NBD-SH) and 7-hydroxycoumarin, respectively. The signaling behavior was analyzed by ratiometry. The selective signaling of H2S over other common metal ions and anions was possible with a detection limit of 1.6 × 10−6 M in an aqueous DMSO solution.