Mitochondrial-targeted red-fluorescent chemodosimeter for hydrogen sulfide signaling and visualizing

A porphyrin based fluorescent chemodosimeter, Psium, which a sulfide-nucleophile reactive ester linker is incorporated between a 2-formylphenyl moiety and a benzyl pyridinium substituted porphyrin fluorophore, has been developed for hydrogen sulfide (H2S) detection. Psium behaved a prominent luminescence “off–on” response to H2S with strong anti-disturbance ability over other potential analytes resulted from the H2S-induced nucleophilic substitution–intramolecular elimination cascade reaction. Systematically spectroscopic studies, NMR/MS/HPLC analysis, and DFT calculation further confirmed the proposed mechanism. Advantages including complete water-solubility, low detection limit (46 nM), high specificity, excellent linear relationship and rapid responding empowered Psium to be utilized in H2S detection in actual samples. CLSM analysis further validated the sensing capability of Psium in living HeLa cells, including the visualization of exogenic-added or endogenic-generated H2S, as well as the localization of mitochondrial H2S. This work could potentially present inspiration and offer insights for exploring of other reactive fluorogenic probes for specific assaying in food or biological specimens.