Rational design and application of sulfur dioxide/formaldehyde reversible near-infrared fluorescence probe

Sulfur dioxide (SO2) exists in widely used food additives, and formaldehyde (HCHO) is often illegally added to fruits, meat products, and aquatic animals to achieve the purpose of preservation, but long-term consumption will cause serious harm to human body. In addition, SO2 and HCHO have strong interaction in the transformation of environmental pollutants and are related to nervous system and cardiovascular diseases in human body. Based on the above considerations, a reversible ratiometric fluorescent probe (BC) was reported to detect the dynamic changes of SO2 and HCHO. The probe has excellent photophysical properties such as fast response (30/120 s), high sensitivity (DL = 8.9/56 nM), large emission displacement (200 nm) and naked eye observation. Moreover, it can double-channel (blue/red) image the fluctuation of SO2 and HCHO content in living HeLa cells and zebrafish. It is worth noting that the low toxicity of probe BC was verified by zebrafish behavioral experiments, which makes it expected to play a practical role in food safety, environmental detection, and early diagnosis of diseases.