A dual-response fluorescence sensor for SO derivatives and polarity and its application in real water and food samples.

As an important gaseous pollutant, SO derivatives generally exist and significantly threaten the environment and organism health. Meanwhile, polarity is a disease-related indicator in the organism's microenvironment, where an unregulated variation may disturb the physiological metabolisms. Hence, a superior FRET-based fluorescent sensor (TLA) is presented to track polarity and sulfur dioxide derivatives by dual emission channel, an elevated red emission at 633 nm with decreasing polarity as well as a reduced red emission at 633 nm and improved blue emission at 449 nm with increasing concentration of SO derivatives. The probe TLA could sensitively detect SO derivatives with ultra-large Stokes shift (273 nm), excellent stability, high selectivity, and low detection limit. Importantly, TLA can accurately detect sulfur dioxide derivatives in real food as well as water samples. Besides, TLA was also fabricated as testing strips and applied to detect SO derivatives in the solution.