Simultaneous detection of Cys/Hcy and H2S through distinct fluorescence channels

Hydrogen sulfide (H2S), cysteine (Cys) and homocysteine (Hcy) play critical roles in human pathologies and there are close interconnections between them in their generation and metabolism in living systems. To elucidate their complex interplay networks, single-molecule fluorescent probes enabling simultaneous detection of H2S and Cys/Hcy from distinct emission channels have been becoming indispensable tools. In this report, we have rationally developed a novel fluorescent probe, NC, for H2S and Cys/Hcy by integrating an amino 7-nitro-1, 2, 3-benzoxadiazole (NBD) moiety and an azide group into the coumarin platform. NC exhibited good selectivity and sensitivity for the discriminatory detection of H2S and Cys/Hcy, and its capability for imaging of intracellular H2S and Cys/Hcy was proved.