利福平分子印迹聚合物微球的制备及性能研究

Study on Recognition Mechanism of Molecularly Imprinted Microsphere Using Rifampicin as Template

以聚乙烯醇1735为分散剂、利福平为模板分子、甲基丙烯酸为功能单体、乙二醇二甲基丙烯酸酯为交联剂,用水溶液微悬浮聚合法制备了利福平分子印迹聚合物微球;在水溶液中,利用静态平衡结合法和Scatchard分析法研究了印迹聚合物的结合能力和选择性.结果表明,利福平溶液的浓度范围在5×10^-5-1×10^-4mol/L内,所制得的印迹聚合物内存在两类不等价的结合位点,根据实验数据计算得到高亲和力结合位点的离解常数和最大表观结合量分别为Kd1=1.08×10^-2mg/mL和Qmax1=14.40 mg/g;低亲和力结合位点的离解常数和最大表观结合量分别为Kd2=7.18×10^-3mg/mL和Qmax2=12.51 mg/g.结合底物的实验结果表明,利福平分子印迹聚合物微球对利福平呈现出了较高的吸附性能和选择识别特性,能较简便地用于利福平的分离和富集.

Molecular imprinted polymer microspheres were synthesized by aqueous suspension polymerization using polyvinyl alcohol 1735（PVA） as dispersive reagent,rifampicin（RFP） as template molecule,MAA as functional monomers and EGDMA as the crosslinker with high selectivity for RFP.The polymers were investigated in equilibrium binding experiments and Scatchard analysis to evaluate the binding characteristics and recognition mechanism of the RFP-molecular imprinted polymer in aqueous solution.Scatchard analysis showed that two binding sites were formed in the imprinted polymer matrix under the studied concentrations.The dissociation constant（Kd1） and the apparent maximum binding capacity（Qmax1） were Kd1=1.08×10-2 mg/mL,Qmax1=14.40 mg/g for high affinity binding sites and Kd2=7.18×10-3 mg/mL,Qmax2=12.51 mg/g for low affinity binding sites.The experiments of binding different substrates showed that the imprinted polymer possessed a high selectivity and a high recognition ability for RFP.The method has advantages of simpler operation and higher accuracy,and may be widely used.