Intracellular biothiols assisted triple-channel imaging of mitochondrial HClO in living cells

A robust mitochondria-targetable fluorescent probe, MBP, for HClO was judiciously constructed by directly connecting a leucomethylene moiety and a pyronin dye through an o-phenylenediamino linker. Under the assistance of intracellular Cys and GSH, MBP can selectively sense HClO through an unrivalled triple-channel fluorescence (peaked at 541, 620, and 690 nm, respectively) turn-on manner for the first time, and the related LOD based on distinct channels data were calculated to be 17, 9, and 31 nM, respectively. This distinctive fluorescence signal response pattern can provide mutual signals for corroboration, which may have the potential to significantly diminish the interferences aroused from external factors, thereby guaranteeing more reliable experimental data outputting. Moreover, MBP also displayed some other powerful properties, including good selectivity, fast response (within 180 s) toward HClO, and excellent mitochondrial-targeting potency (the corresponding Pearson's coefficient was determined to be 0.96). Noteworthily, the application of MBP for triple channel fluorescence image of exogenous/endogenous HClO in living cells has been successfully achieved, thereby holding the potential for biological investigations.