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Published on: June 16, 2020
Aptamer-functionalized pH-responsive polymer-modified magnetic nanoparticles for specific enrichment and sensitive
Yao Ma1, Liping Zhao1, Linsen Li1
1Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, 5 South Zhongguancun Street, Beijing, 100081, China.
Abstract:
A new type of aptamer-functionalized pH-responsive polymer-modified magnetic nanoparticles (ApMNPs) is introduced for specific enrichment and sensitive determination of lactoferrin (Lf) in complex matrixes. In the construction, Fe3O4@3-(Triethoxysilyl)propylmethacrylate@poly(4-Vinyl-1, 3-dioxolan-2-one-acrylic acid) (Fe3O4@MPS@p(VEC-AA)) were synthesized as pH-responsive polymer-modified magnetic nanoparticles (pMNPs) through free radical polymerization to increase the tunable interaction. Lf-binding aptamers were conjugated onto pMNPs through the reaction of amino-group in aptamer and epoxide-group in VEC, innovatively applied to prepare Lf-ApMNPs. On the basis of the synergistic effect of specific affinity of aptamer on Lf and tunable hydrophobic/hydrophilic property of pH-responsive polymer, Lf-ApMNPs presented good selectivity toward Lf, excellent adsorption capacity (as high as 233.9 mg g-1), as well as good recoveries in the range 93.6-99.6% in Lf-related nutrition samples. Significantly, the introduction of pH-responsive monomer (AA) effectively regulated the adsorption-desorption process of Lf, with the function similar to a switch. Moreover, the good performances of Ct-ApMNPs toward α-Chymotrypsin showed that ApMNPs exhibited universality to other proteins through easily changing the binding aptamer, thereby offering a facile and efficient approach for specific enrichment and sensitive determination of targets in real biological samples.
