A Novel Colorimetric Fluorescent Probe for SO₂ and Its Application in Living Cells Imaging.

A novel chromenylium-based fluorescent probe was exploited for sulphur dioxide (SO₂) detecting. The probe displayed a remarkable fluorescence turn-on response towards SO₂ based on the nucleophilic addition reaction to the carbon-carbon double bond with 105 nm Stock shift. The probe was successfully applied for the quantification of SO₂.The linear detection range was from 0-160 μM with the detection limit as low as 99.27 nM. It also exhibited high selectivity for SO₂ than other reactive species and amino acids. Furthermore, cell staining experiments indicated that the probe was cell membrane permeable and could be used for high-performance imaging of SO₂ in living cells. The superior properties of the probe made it highly promising for use in chemical and biological applications.