Novel dual-channel ratiometric fluorescence probe for SO2 detection in food and bioimaging applications based on FRET mechanism.

SO₂ is commonly used to ensure the safety of food, but englobing of excessive SO₂ poses serious risks to human health. Additionally, as fourth gaseous signaling molecule, it plays a critical role in various physiological processes. Therefore, monitoring the concentration of SO₂ in food and cells is crucial for correlative research and disease diagnosis. Herein, two ratiometric fluorescence probes (EHDA and EHDB) have been synthesized for detecting sulfite based on fluorescence resonance energy transfer (FRET). Undoubtedly, EHDA as the preferable probe due to its superior discernibility to SO₃^2- than that of EHDB. Moreover, EHDA featured rapid response, high sensitivity, excellent selectivity, and low cytotoxicity in physiological pH. Besides, EHDA could be expanded to establish convenient smartphone SO₂ sensing platform through innovatively loading EHDA on polyvinylidene fluoride membrane. Fortunately, EHDA has been utilized for determining SO₃^2- in food samples and imaging the fluctuation of sulfite in living cells and zebrafish.