title: Composite QDs@MIP nanospheres for specific recognition and direct fluorescent quantification of pesticides in aqueous media.
abstract: 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 50-600 ng/mL. The present studies provide a new and general strategy to fabricate other multifunctional (luminescent and magnetic) inorganic-organic MIP nanocomposites with highly selective recognition ability in aqueous media and are pretty desirable for biomedical/chemical sensing applications.
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Analytical Chemistry Department, School of Science, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China.
authors.forename: Yaoyao
authors.initials: Y
authors.lastname: Zhao
authors.forename: Yingxin
authors.initials: Y
authors.lastname: Ma
authors.forename: Hao
authors.initials: H
authors.lastname: Li
authors.forename: Leyu
authors.initials: L
authors.lastname: Wang
mesh_terms: D002138:Calibration; D005456:Fluorescent Dyes / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D008863:Microspheres; D010575:Pesticides / Q000032:analysis*; D013050:Spectrometry, Fluorescence; D014867:Water / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; D010575:Pesticides; D014867:Water