Chromene-derived red-fluorescent probes for sulfite detection in food and living cells based on an integrated ICT&PET platform

Sulfite, widely used in food and pharmaceutical industries, poses significant health and safety concerns, necessitating efficient detection methods. This study introduces three novel red fluorescent probes (MCC -BT, MCC -TI, and MCC -DM), synthesized by integrating chromene derivatives with various electron -withdrawing groups. These probes effectively detect sulfite in both food samples and living cells, leveraging a mechanism transition from intramolecular charge transfer (ICT) to photo -induced electron transfer (PET). They demonstrate low detection limits (2.0 mu M, 0.42 mu M, and 0.34 mu M, respectively) and offer advantages including large Stokes shifts, minimal interference, and colorimetric capabilities. We also developed smartphone-compatible test paper strips for convenient sulfite detection in real -world samples. The probes' effectiveness is further evidenced through sulfite quantification in Traditional Chinese Medicine ingredients. Additionally, their robust fluorescent imaging potential for cellular sulfite sensing highlights their significant contribution to analytical chemistry and biomedical research.