Visualizing Hydrogen Sulfide in Mitochondria and Lysosome of Living Cells and in Tumors of Living Mice with Positively Charged Fluorescent Chemosensors

Two fluorescent chemosenors, Mito-HS and Lyso-HS, were rationally designed and synthesized with positive charge at physiological conditions. The positive charge showed triple functions as target moieties for subcellular mitochondria and lysosome of living cells, soluble moieties for chemosenors, as well as effective sequesters of HS^– (H₂S at physiological conditions). These two probes showed faster and more efficient fluorescence H₂S detection than the similar literature-reported probe without positive charge. In addition, visualizing of hydrogen sulfide in tumors of living mice was successfully achieved for the first time using the probe Mito-HS.