Imaging the dynamic processes of hydrogen sulfide using a rapid “turn-on” mitochondria-targeting fluorescent probe

Hydrogen sulfide (H2S) is a signal molecule that is significantly involved in cell protection, vascular regulation, and neuro-transmission. Nevertheless, abnormal levels of H2S are intimately relevant to Alzheimer’s disease, liver cirrhosis, diabetes mellitus, and Down syndrome. To improve the H2S detection in vitro and in vivo, we developed RDM-H2S, a novel red-emission fluorescent probe. RDM-H2S has a rapid response (120 s), high sensitivity (LOD = 310 nM), obvious response degree (234 folds), relatively long excitation/emission wavelength (565 nm/620 nm), and steady emission in pH 6–9. In addition, RDM-H2S showed high specificity to H2S in various species. Due to the low cytotoxicity of RDM-H2S, it was beneficial to the application of biological depth imaging. In addition, RDM-H2S could measure exogenous and endogenous H2S in distinct biological models, such as HeLa cells and zebrafish. Besides, RDM-H2S had excellent mitochondrial targeting ability and could be used to monitor H2S in living mice. RDM-H2S could visualize endogenous H2S in different tissues and 4T1-xenograft tumor mice. Additionally, RDM-H2S also exhibited immense application potential for the visualization of H2S in the process of inflammation. RDM-H2S was applied for measuring the level of H2S in human plasma samples. Consequently, RDM-H2S was determined to be a valuable tool for monitoring H2S in pre-clinical diagnosis.