A Fluorescence Probe for HSO₃^- Based on Benzofurazan

A fluorescent probe for the detection of bisulfite (HSO₃^-) was designed and synthesized using 4-chloro-7-nitrobenzofurazan (NBD-Cl) and imidazole-4-carbaldehyde. Its structure was characterized with ¹H-NMR and MS. The fluorescence test results showed that the compound exhibited a fluorescence-enhancing response to HSO₃^- in aqueous solution of dimethyl sulfoxide (DMSO), but other anions had almost no similar fluorescence recognition for the compound under the same conditions. Therefore the fluorescent compound has a specific fluorescence recognition effect on HSO₃^- and is an effective HSO₃^- fluorescent probe.