Construction of a mitochondria-targeted near-infrared fluorescence turn-on fluorescent probe for HS detection and imaging in living cells and drug-induced mice inflammatory models.

The mechanism of the interaction between the signaling molecule hydrogen sulfide (HS) and mitochondria and its related diseases is difficult to elusive. Thus it is urgent to develop effective methods and tools to visualize HS in mitochondria and in vivo. In this work, a robust mitochondrial-targeting NIR fluorescence "turn-on" fluorescent probe, NIR1, was reported, by adopting a Changsha-OH near-infrared (NIR) dye as the NIR fluorophore, a 2,4-dinitrophenyl (DNB) moiety as both the responsive site of the HS and the fluorescence quenching group of the NIR fluorophore, and an oxygen onium ion site as the mitochondria-targeting group, for the detection and analysis of HS in living Raw 264.7 cells and drug-induced inflammatory mice models. NIR1 exhibited a much smaller background fluorescence signal in lack of HS, whereas strong enhanced NIR fluorescence "turn-on" was detected in the presence of HS, these results showed a low detection limit (30.2 nM) for quantitative detection of HS in aqueous solutions with concentrations ranging from 0 to 1 μM HS. These characteristics were beneficial to direct detection and imaging analysis of HS in complicated biosystems. Therefore, first, NIR1 was applied for the NIR detection of mitochondrial HS in living inflammatory cells with satisfactory results. Finally, NIR1 was applied to detect HS in drug-induced inflammatory mice models with agreeable results, demonstrating that NIR1 as a molecular tool has an excellent practical application in the study of the interaction between inflammatory and HS.