Fluorescent Red GK as a fluorescent probe for selective detection of bisulfite anions

A coumarin-based dye, Fluorescent Red GK, was developed for the detection of bisulfite anions. The probe has exhibited high selectivity and sensitivity against other anions at room temperature. Upon addition of HSO3−, the strong fluorescence of Fluorescent Red GK was severely quenched and its color changed significantly from orange to colorless under illumination with a UV lamp. The color of the solution was also changed from pink to colorless. As a result, it can be used as a specific colorimetric and fluorescent probe for bisulfite anions. In addition, the detection limit was as low as 1.76 μM. The results showed that the Fluorescent Red GK could be used in the design of the fluorescent probe for detecting HSO3− in aqueous solution. Furthermore, the probe has been used for determination of bisulfite in sugar samples with satisfactory results.