A colorimetric and ratiometric fluorescent probe for the rapid and sensitive detection of sulfite in sugar

A colorimetric and ratiometric fluorescent probe was developed for the detection of sulfite in sugar. The probe underwent a Michael addition reaction with sulfite, which resulted in significant changes in fluorescence ratios. The probe displayed a fast response (within 30 s) and high selectivity towards sulfite over other anions and bio-thiols. The fluorescence intensity ratios were linearly related to the concentration of SO32− ranging from 0 to 15 μM, and the limit of detection was determined to be as low as 12 nM. The probe was employed to determine the concentration of sulfite in sugar with good recovery.