Highly sensitive detection of cobalt through fluorescence changes in β-cyclodextrin-bimane complexes

A supramolecular complex ofsyn-(methyl,methyl)bimane (1) and β-cyclodextrin demonstrates a sensitive (limit of detection = 0.60 nM) and selective fluorescence turn-off response in the presence of cobalt in aqueous media, with calibration curves enabling quantitation in solution and using filter papers on which bimane and cyclodextrin were adsorbed.¹H NMR spectroscopy provides insight into interactions underlying the sensor performance.