A new spectrofluorometric method for the determination of nicotine base on the inclusion interaction of methylene blue and cucurbit[7]uril

A new method for the fluorometric detection of the nicotine in water is presented. Use of methylene blue (MB) bound to cucurbit[7]uril (CB7) affords the competitive fluorescence inclusion method for the detection of nicotine in aqueous solution. At the same time, the characteristics of host–guest complex between CB7 and MB were studied. It was found that the fluorescence intensity of MB regularly increased upon the addition of CB7. While an appropriate amount of nicotine was added to the MB–CB7 system, the fluorescence intensity of the system quenched remarkably. The method has a linear range of 0.2 ∼ 8.0 μg mL −1 and a detection of 0.05 μg mL −1 . The method was applied satisfactorily to determine nicotine in cigarettes.