A highly sensitive and responsive fluorescent probe based on 6-azide-chroman dye for detection and imaging of hydrogen sulfide in cells

Hydrogen sulfide or H₂S is known as an important gasotransmitter involved in regulation of many physiological and pathological processes. Since a small amount of H₂S is produced by endogenous cells in the body and microorganisms in the gastrointestinal tract (GI tract), the current detection probes are limited for their use in measurement of unpretentious change of H₂S level both in vitro and in vivo. Therefore, development of a highly sensitive and responsive fluorescent probe for measurement of H₂S in vivo is of great significance for investigation of H₂S function and toxicity. Here, we designed a novel fluorescent probe AC-N₃ through introducing azide in 6-position of chroman dye based on the hypothesis that 6-position (para-position) of chromone may be a potential trigger of fluorescent properties. The probe AC-N₃ exhibits a better selectivity without interference from analytes, high sensitivity and little cytotoxicity. In addition, we confirmed that the conversion of electron-donating group in 6-position of chromone can trigger the change of fluorescence, which can be applied to design of other fluorescent probes.