A novel ratiometric fluorescent probe for differential detection of HSO and ClO and application in cell imaging and tumor recognition.

By connecting 1,8-naphthalimide and indole sulfonate, a ratio fluorescent probe capable of differential detection of hydrogen sulfite and hypochlorite was synthesized for the first time. It was able to achieve the qualitative detection of HSO and ClO with high sensitivity and selectivity, respectively. It provides a multi-purpose probe and is based on different emission channels without mutual interference. The probe has the advantages of larger Stokes shift (ClO: 115 nm, HSO: 88 nm), longer λ (ClO: 515 nm, HSO: 548 nm) and better water solubility (DMF/PBS = 1:99, v/v). In addition, the probe is a ratio fluorescence probe, which can detect fluorescence intensity with two different emission waves. It provides internal self-calibration, reduces interference from the background and increases detection accuracy. In vitro cytotoxicity and imaging experiments show that the probe can effectively perform the detection of exogenous HSO and ClO in cells. It can also achieve the detection of HSO and ClO in the plasma environment. Because the probe can detect endogenous ClO, it also has a good prospect for biological application in identifying tumor cells. Graphical abstract.