A Magnetic Sensing Probe of Zinc Oxide Decorated Carbon Foam and Nitrogen-Doped Graphene Quantum dots in a Selective Polymer for the Determination of Florfenicol in Milk

Abstract

The purpose of this thesis was to develop an optosensor based on fluorescence quenching for the determination of florfenicol. The sensing probe was composed of nitrogen-doped graphene quantum dots, zinc oxide decorated carbon foam and magnetite nanoparticles in a molecularly imprinted polymer (N-GQDs/ZnO*CF/Fe3O4/MIP). The fluorescence intensity of the N-GQDs/ZnO*CF/Fe3O4/MIP probe was emitted at 410 nm with an excitation wavelength of 330 nm. The intensity of fluorescence emissions decreased linearly with increasing the concentration of florfenicol from 0.50 to 100 ?g L-1. The limit of detection and limit of quantification were 0.17 and 0.55 ?g L-1, respectively. The developed optosensor based on the nanocomposite probe was applied to determine florfenicol in milk samples. Recoveries from 90.5 % to 101.5 % were achieved with a relative standard deviation (RSD) lower than 3 %. The real-sample analysis results of the developed method agreed well with the HPLC analysis results. The developed optosensor showed high sensitivity and good selectivity, and can be applied for the determination of other substances in various samples by optimizing measurement conditions.

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