Lysozyme-targeted ratiometric fluorescent probe for SO2 in living cells

Sulfur dioxide (SO2) as a common environmental pollutant, participates in a variety of physiology and pathological processes in vivo. Lysosomes are considered to be cleaners of living cells and play a vital role in the process of metabolism. Exposure to excess SO2 will result in the increase risk of lysosomal dysfunction and induce multiple diseases. Herein a smart fluorescent probe LYSO-SO2 is developed, which achieved the ratio (F561 nm/F634 nm) identification of SO2 in vitro. LYSO-SO2 showed high sensitivity (detection limit 15.8 nM), rapidly response (within 5 s), and excellent selectivity. Additionally, this probe LYSO-SO2 has been successfully applied to the ratio monitoring SO2 in lysosomes which may provide an effective quantitative method for studying the physiological and pathological functions of SO2 in living cells.