Dual-site mitochondria-targeted fluorescent probe for simultaneous distinguishing detection of hypochlorite and SO2 derivatives in real water samples and bioimaging

SO2 derivatives and hypochlorite are ubiquitous in the environment and organisms, but excessive SO2 derivatives or ClO− can cause environmental pollution and serious diseases. Therefore, fluorescent probes to simultaneously test SO2 derivatives and ClO− in vitro and vivo are greatly needed. However, reported fluorescent probes with single recognition site for SO2 derivatives and ClO− detection have a competition and cross-talk, making the test inaccurate. So a novel dual-site mitochondria-targeted fluorescent probe (probe BEDB) was developed and could respectively response to SO2 derivatives and ClO− by distinct fluorescence with desirable properties, such as good selectivity, high sensibility and rapid response. The sensing mechanisms of SO32− and ClO− by probe BEDB were confirmed as nucleophilic addition and oxidation respectively by HPLC and HR-MS. Probe BEDB was used to accurately detect SO32− or ClO− in real samples, including river water, tap water and Tremella. Based on colorimetric methods, the fast-testing tube of probe BEDB could quickly and easily test ClO− or SO2 derivatives in real samples. Moreover, the probe was also effectively applicable to image SO2 derivatives and ClO− in living cells and zebrafish with mitochondria-targeted, and a crosstalk between SO2 derivatives and ClO− in the oxidative stress of acute liver injury models was also verified. Therefore, the dual-site fluorescent probe is a potent molecular tool for simultaneous distinguishing detection of SO2 derivatives and ClO−.