A Novel Water-soluble Triphenylamine-based Fluorescent Probes for Real-time Monitoring of HSO3⁻/SO32⁻ in Food Samples and Living Cells.

Sulfur dioxide (SO2) is ubiquitously present in environmental and biological samples, predominantly as HSO3-/SO32- in aqueous solutions. While their controlled utilization underpins industrial and agricultural processes, excessive residual SO₂ poses severe threats to ecological sustainability and physiological homeostasis in organisms. To address the pressing need for rapid, real-time monitoring of these species, we developed a novel D-π-A structured fluorescent probe, TPA-SO₂, engineered through rational integration of triphenylamine as a robust electron-donating moiety. This probe exhibits excellent water solubility. Photophysical experiments revealed that the probe possesses high selectivity, instantaneous response (< 10 s), and a low detection limit (21.4 nM) for SO2 derivatives in PBS solution. Experimental results demonstrate the probe's applicability for detecting SO2 residues in various food products and for imaging SO2 derivatives in living cells.