铜离子配位的分子印迹聚合物的分子识别特性研究

Molecular Recognition Characteristics of Cu Complex Imprinted Polymer

为了探讨金属配位分子印迹聚合物的识别机理,提高分子印迹聚合物分离的选择性与亲和性,制备了金属铜离子与2,2＇-联吡啶配合物的分子印迹聚合物,并用平衡吸附法系统研究了分子印迹聚合物对铜(Ⅱ)-2,2＇-联吡啶配合物的识别.证明印迹聚合物对铜(Ⅱ)-2,2＇-联吡啶具有选择性识别能力,Scatchard分析显示在聚合物中存在两类不同的结合位点,求得结合位点的离解常数和最大结合量,并研究了识别过程的动力学.结果表明金属配位分子印迹聚合物有较高的特异性识别能力和较快的动力学结合过程.

With the goal of improving the affinity and specificity in molecularly imprinted polymers, metal complexing polymer matrices capable of specific recognition and binding to metal - coordinating substrates have been prepared by molecular imprinting technology. The synthesis of these materials involves preorganization of 4 - vinylpyridine as monomer, with copper - 2,2' - dipyridyl as template, and subsequent polymerization with a large excess of ethylene glycol dimethacrylate as the cross - linking agent. The characteristics of its substrate binding selectivities and specificities to the template was investigated in details. Scatchard analysis demonstrated that two kinds of binding site were formed in the imprinted polymers. Their dissociation constants were estimated to be 30 mu mol/L and 0.45 mmol/L, respectively. Factors that influenced rebinding of the imprinted polymer including the concentration of copper (II) acetate, the kind of cation and anion, were explored. The results show that the selective recognition of copper - 2, 2' - dipyridyl by the polymer was distinctly enhanced at the optimum concentration of copper (II) acetate, as compared with the control polymer with the same chemical composition. Finally, the substrate selectivity of imprinted polymer and non-imprinted polymer was investigated.