A dual-emission and mitochondria-targeted fluorescent probe for rapid detection of SO2 derivatives and its imaging in living cells.

A novel mitochondria-targeted fluorescent probe for sensing SO2 derivatives was constructed by integrating phenanthroimidazole and cyanine moieties. Excited by different channels, this probe exhibited unique dual-channel fluorescence-enhanced emissions and colorimetric response to HSO3- quickly (less than 20 s). The sensing process was confirmed to undergo nucleophilic addition of HSO3- to C˭C double bond in the probe Mito-PTB via NMR and HRMS analyses. Furthermore, fluorescence co-localization studies demonstrated that the probe Mito-PTB was a mitochondria-targetable fluorescent probe for SO2 derivatives with good cell membrane permeability. Thus, probe Mito-PTB has the potential applications to explore the role played by SO2 derivatives in biology.