A mitochondria-targeted near-infrared probe for colorimetric and ratiometric fluorescence detection of hypochlorite in living cells

Abstract

In this study, we report a near-infrared (NIR) fluorescent probe (CMBI) for the detection of hypochlorite (ClO⁻), which displays colorimetric and ratiometric fluorescence dual responses towards ClO⁻. The probe can detect ClO⁻ with high selectivity, fast response (within 90 s) as well as low detection limit (33 nM). An oxidation reaction was proposed for the sensing mechanism, which was confirmed by ¹H NMR and HR-MS spectra. Fluorescence co-localization studies demonstrated that CMBI was a specific mitochondria-targeted fluorescent probe for ClO⁻ with excellent cell membrane permeability. Furthermore, confocal fluorescence images of HeLa cell indicated that CMBI could be used for monitoring intracellular ClO⁻ in living cells by ratiometric fluorescence imaging.