Composite QDs@MIP Nanospheres for Specific Recognition and Direct Fluorescent Quantification of Pesticides in Aqueous Media

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• 作者：Yaoyao Zhao ; Yingxin Ma ; Hao Li ; Leyu Wang
• 刊名：Analytical Chemistry
• 出版年：2012
• 出版时间：January 3, 2012
• 年：2012
• 卷：84
• 期：1
• 页码：386-395
• 全文大小：1062K
• 年卷期：v.84,no.1(January 3, 2012)
• ISSN：1520-6882

文摘

Quantum dots (QDs)-based molecularly imprinted polymer (MIP) composite nanospheres were successfully prepared via a facile and versatile ultrasonication-assisted encapsulation method. Unlike the hydrogen-bond-based MIPs, these so-prepared QDs-MIP composite nanospheres, relying on the interaction including van der Waals forces and hydrophobic forces, demonstrated excellent selectivity in aqueous media. Their small particle sizes and carboxyl-enriched polymer matrixes give rise to their good dispersibility and stability in aqueous solution, and faster adsorption and desorption kinetics, which further make them extensively applicable for chemical/biological sensors in aqueous media. Based on the fluorescence quenching via template analytes (diazinon) rebinding into the recognition cavities in the polymer matrixes, the QDs-MIP nanospheres were successfully applied to the direct fluorescence quantification of diazinon, independent of extracting templates from the MIP nanospheres, as well as further complicated and time-consuming assays. This novel method can selectively and sensitively detect down to 50 ng/mL of diazinon in water, and a linear relationship has been obtained covering the concentration range of 50鈥?00 ng/mL. The present studies provide a new and general strategy to fabricate other multifunctional (luminescent and magnetic) inorganic鈥搊rganic MIP nanocomposites with highly selective recognition ability in aqueous media and are pretty desirable for biomedical/chemical sensing applications.