Abstract
Water-soluble CdTe quantum dots of different sizes capped with thioglycolic acid (TGA-CdTe QDs) were synthesised via a microwave-assisted method. It was found that melamine could quench the fluorescence emission of TGA-CdTe QDs in aqueous solution. Based on this, a novel method for the determination of melamine has been developed. Under optimum conditions, the fluorescence intensity of TGA-CdTe QDs versus melamine concentrations gave a linear response according to the Stern–Volmer equation. The proposed method has been successfully used to detect melamine in liquid milk with a detection limit of 0.04 mg L−1, and the whole process including sample pre-treatment could be accomplished within 30 min. The obvious merits provided by this method, such as simplicity, rapidity, low cost and high sensitivity would make it promising for on-site screening of melamine adulterant in milk products. The possible mechanism involved in the interaction of melamine with TGA-CdTe QDs is discussed.
Acknowledgements
This work was financially supported by the National Natural Science Foundation of China (No. 20905031) and the research start-up fund of Jilin University (No. 4305050102H6).
Notes
Minwei Zhang and Hong Ping contributed equally to this work.