A colorimetric and fluorescence turn-off probe 10-(4-azido phenyl)-5,5-difluoro-5h-dipyrrolo1,2-c:1’,2’-f1,3,2 diazaborinin-4-ium-5-uide, 1 , for selective detection of H 2 S is reported. The probe displayed a robust decrease in fluorescence intensity with high sensitivity, specificity and least toxicity to detect exogenous H 2 S and also in live normal human oral fibroblast cells loaded with probe 1 . The detection limit of probe 1 being 0.17 µm for H 2 S. Graphic abstract A colorimetric and fluorescence turn-off BODIPY probe 1 , for selective detection of exogenous H 2 S in live normal human oral fibroblast cells loaded with probe 1 and poisonous H 2 S gas formed under biodegradation in sewage waters and water tanks and corroded pipe lines. The detection limit of probe 1 being 0.17 μM