A fluorescent probe for ultra-wide range detection of SO2 in food, traditional Chinese medicine, organisms and environment.

Sulfur dioxide (SO2) has long been recognized as a hazardous environmental pollutant, and excessive intake of SO2 and its derivatives (HSO3-/SO32-) may be harmful to human health. A fluorescent probe capable of quantitative sulfite detection (0.755 μM - 500 μM), named RPB-R, was developed to exhibit chromogenic and red fluorescence turn-on responses. The probe demonstrates ultrafast detection kinetics (<5 s), low detection limit (0.755 μM), and broad concentration detection capability spanning three orders of magnitude, establishing its technical superiority for environmental monitoring and food detection applications. RPB-R is capable of easily and accurately determining the sulfite content of different real food products and traditional Chinese medicines, thus allowing judgments about the safety and compliance of these products. In particular, RPB-R was incorporated into agarose, PVA film and filter paper to serve as convenient, inexpensive and portable devices for rapid and visual detection of SO2 gas. Furthermore, RPB-R was successfully used for monitoring and imaging sulfites in MCF-7 cells with a high contrast ratio.