SURFACE IMPRINTED NANOPARTICELS FOR SELECTIVE ENRICHMENT OF DRUGS IN HUMAN SERUM AND URINE

Molecularly imprinted polymers (MIPs), featuring high specificity, good stability, ease of preparation, and low cost, are receiving remarkable attention as smart and robust materials for chemical and biochemical analyses. However, MIPs are still suffering from several problems, such as incomplete template removal, slow mass transfer, poor site accessibility, or heterogeneous distribution of binding sites.

In our work, the superparamagnetic core-shell MIP nanoparticles were prepared via surface initiated reversible addition fragmentation chain transfer (si-RAFT) polymerization using enrofloxacin as template. The surface morphology and imprinted behavior were investigated and optimized. The living/controlled nature of RAFT reaction allowed the successful construction of well-defined imprinted polymer layer outside the Fe₃O₄ core, which favors fast mass transfer and rapid binding kinetics. The target binding assays demonstrated the fast adsorption kinetics and high imprinting efficiency of Fe₃O₄@MIPs. Combined with RP-HPLC, the prepared MIP nanoparticles were used for the selective enrichment and analysis of four fluoroquinolones (FQs) in human serum and urine samples. Further, in complex biological samples, imprinting sites of MIPs could be covered by large molecules such as proteins in the matrix. To overcome this problem, hydrophilic macro-chain transfer agents (macro-CTA) was added in the RAFT polymerization to construct MIPs with a hydrophilic surface. Further binding capacity assay revealed desirable adsorption capacity, imprinting efficiency and high selectivity of Fe₃O₄@MIP towards templates. Such kind of magnetic MIP revealed great prospect in separation and enrichment of trace analysts in complex biological samples.

Reference

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[2] He Y., Huang Y., Jin Y., Liu X., Liu G., Zhao R. (2014) Well-Defined Nanostructured Surface-Imprinted Polymers for Highly Selective Magnetic Separation of Fluoroquinolones in Human Urine. ACS Appl. Mater. Interfaces 6: 9634-9642.

[3] Su L., Jin Y., Huang Y., Zhao R. (2017) Surface-imprinted magnetic nanoparticles for the selective enrichment and fast separation of fluoroquinolones in human serum. J. Sep. Sci. 40: 2269-2277.

[4] Sheng L., Jin Y., He Y., Huang Y., Yan L., Zhao R. (2017) Well-defined magnetic surface imprinted nanoparticles for selective enrichment of 2,4-dichlorophenoxyacetic acid in real samples. Talanta 174: 725-732.

[5] Financial supports from NNSFC are appreciated.