Fe3O4@PEG@SiO2人工抗体的制备及其对噻吩磺隆的吸附性能

以FeCl2·4H2O和FeCl3·6H2O为原料采用共沉淀法制备Fe3O4磁性纳米粒子，在其表面修饰聚乙二醇 2000（PEG-2000），在所得的修饰了PEG-2000的Fe3O4磁性纳米粒子溶液中加入模板分子噻吩磺隆、交联剂正硅酸乙酯和催化剂氨水，水解后制得印迹了噻吩磺隆的Fe3O4@PEG@SiO2人工抗体。用体积比为1:4的乙酸和丙酮溶液为洗脱剂，洗脱位于SiO2壳层中的印迹分子，形成具有与印迹分子结构、大小和功能基团互补的特异性识别位点空穴。制备的Fe3O4@PEG@SiO2人工抗体对目标分析物噻吩磺隆分子选择性识别和吸附，对噻吩磺隆的最大饱和结合量为41.28 mg·g-1，前30 min内，其吸附速率为0.45 mg·(min·g)-1，分别是非印迹方法的5.34倍和3.46倍。

Preparation of Fe3O4@PEG@SiO2 artificial antibody and its adsorption performance for thifensulfuron methyl

Fe3O4@PEG@SiO2 artificial antibody was synthesized through the coprecipitation and hydrolysis copolymerization method, which can selectively recognize target analyte. Firstly, Fe3O4 magnetic nanoparticles cores of the artificial antibody were obtained by the coprecipitation reaction of FeCl2·4H2O with FeCl3·6H2O as raw materials. Subsequently, the surface of Fe3O4 magnetic nanoparticles were modified by monolayer of hydroxyl group using polyethylene glycol 2000(PEG-2000). Moreover, the thifensulfuron methyl-imprinted Fe3O4@PEG@SiO2 were prepared by adding imprinting molecule (thifensulfuron methyl), crosslinking agent (tetraethyl orthosilicate), catalyst (ammonia aqueous, 25%) into a known amount of hydroxyl-capped Fe3O4 magnetic nanoparticles through the hydrolysis copolymerization reaction. What's more, the thifensulfuron methyl molecules embedded into SiO2 shell layer were eluted by acetic acid and acetone mixed solution (volume ratio=1:4) to generate specific recognition cavities which suit imprinting molecule in structure, size and complementation in functional groups. Finally, the resultant Fe3O4@PEG@SiO2 artificial antibody can selectively recognize and sensibly adsorb the trace molecule of thifensulfuron methyl. The results demonstrated that the maximum binding capacity saturated from Fe3O4@PEG@SiO2 artificial antibody to thifensulfuron methyl is 41.28 mg·g-1, which is 5.34 times as the non-imprint product. The adsorption rate is 0.45 mg·(min·g)-1, which is 3.46 times as the non-imprint material.