A near-infrared and mitochondria-targeted fluorescence probe for ratiometric monitoring of sulfur dioxide derivatives in living cells.

A promising near-infrared emissive and mitochondria-targeted fluorescence probe (SNB) for the ratiometric detection of sulfur dioxide derivatives with a novel reaction mechanism was developed on the basis of FRET and the ICT platform. Probe SNB showed favorable fluorescence properties, including an active NIR emission signal (671 nm), ultra-large Stokes shift (251 nm) and an ultra-broad emission band gap (193 nm). Furthermore, SNB was applied to detect sulfur dioxide derivatives with a low detection limit (17 nM), excellent sensitivity and exceptional selectivity. Of greater significance, SNB also successfully implemented the real-time and ratiometric surveillance for exogenous or endogenous sulfur dioxide derivatives in living HeLa, L-O2 and HepG2 cells. Interestingly, SNB possessed a subcellular organelle targeting ability with a preferred co-localization coefficient of 0.91 for mitochondria, which revealed its promising potential in the detection of subcellular sulfur dioxide derivatives.