A ratiometric fluorescent probe for SO2 derivatives based on a new coumarin-hemicyanine dye in living cells

A new coumarin-hemicyanine dye was synthesized and used as a ratiometric fluorescent probe for SO2 derivatives (HSO3-/SO32-). The probe showed deep-red fluorescence, ratiometric response, good selectivity, low detection limit and well-separated emission bands. Moreover, the probe was mitochondria-targeted, and was applied to image SO2 derivatives in living cells.