Red-Emission Probe for Ratiometric Fluorescent Detection of Bisulfite and Its Application in Live Animals and Food Samples

[Image: see text] Key roles of bisulfite (HSO(3)(–)) in food quality assurance and human health necessitate a reliable analytical method for rapid, sensitive, and selective detection of HSO(3)(–). Herein, a new red-emitting ratiometric fluorescence probe, BIQ, is reported for sensitive and selective detection of HSO(3)(–) in food samples and live animals. Probe BIQ recognizes HSO(3)(–) via a 1,4-nucleophilic addition reaction. As a result of this specific reaction, emission intensities at 625 and 475 nm are dramatically changed, allowing the detection of HSO(3)(–) in a ratiometric fluorescence model in an aqueous solution. The obvious changes of solution color from pink to transparent and fluorescence color from rose-red to cyan allow the detection of HSO(3)(–) by naked eyes. Furthermore, probe BIQ has fast response in color and fluorescence (<2 min), excellent selectivity, and a low detection limit (0.29 μM), which enables its application in HSO(3)(–) detection in food samples and live organisms. The practical applications of probe BIQ are then demonstrated by the visualization of HSO(3)(–) in live animals (zebrafish and nude mouse) as well as the determination of HSO(3)(–) in white wine and sugar.