A sequential dual-key-dual-lock fluorescent probe for detection of SO2 and H2O2 in cells and mice

Oxidative stress refers to the disruption of the oxidative balance in the body, which can lead to various pathological conditions. There have been more and more studies on the interaction between H2O2 and reducing agents. Herein, a novel fluorescent probe BN-DUAL was designed and synthesized for sequential detecting SO2 and H2O2 with the “dual-key-dual-lock” strategy. To the best of our knowledge, this work is the first application of “dual-key-dual-lock” strategy to identify SO2 and H2O2. BN-DUAL interacted with SO2 to generate an intermediate product BN-SO2, and the pink fluorescence of the probe quenched. BN-SO2 reacted with H2O2 to generate BN with noticeable yellow fluorescence. In addition, the probe does not react directly with hydrogen peroxide. The “dual-key-dual-lock” strategy can improve the selectivity and accuracy of the detection of SO2 and H2O2 in cells and in vivo. The signal changes of the two channels can make the detection clearer and more visualized, which has been verified by imaging exogenous and endogenous SO2/H2O2 in cells and mice. This probe provides a better method to research the oxidative stress caused by SO2 and H2O2.