Computational approach using Density Functional Theory (DFT) method and PM3 method, the geometry optimization, energy and binding energy of imprinted molecule with functional monomer were studied by Gaussian 03. Chlorogenic acid is taken as template molecule, and acrylamide (AM), acrylic acid (AA), 4-vinylpyridine (4-VP) and 2-vinylpyridine (2-VP) are taken as functional monomer, respectively. The order of the binding energy of chlorogenic acid with the above monomers was discussed, and the highest binding energy is AM. The molecular imprinting polymer (MIP) membranes with chlorogenic acid as template were prepared by UV irradiation polymerization method using AM, AA, 4-VP and 2-VP as functional monomer, respectively; polyvinylidene fluoride microfiltration membranes were used as support. The experimental results about measuring the adsorption of substrate on the several imprinted membranes are consistent with theoretical calculation results. Scatchard analysis showed that two non-equivalence binding sites were formed in the molecularly imprinted composite membranes under the studied concentration, the dissociation constants (Kd) of binding sites were 0.151 and 0.480 mmol/L. The adsorption and permeation experiment for substrates indicated that the imprinted composite membranes gave a higher adsorption capability for chlorogenic acid, combining quantities are 14.934 and 28.123 μmol/g.%以绿原酸为模板分子,以丙烯酰胺(AM)、丙烯酸(AA)、4-乙烯基吡啶(4-VP)、2-乙烯基吡啶(2-VP)四种物质分别作为功能单体,使用密度泛函理论(DFF)方法和PM3半经验法,运用Gaussian 03软件模拟模板分子与不同功能单体的分子印迹聚合物预组装体系的构型、能量及复合反应的结合能(△E),以讨论不同功能单体对分子印迹聚合物识别性能的影响,结果丙烯酰胺的印迹效应最好.以聚偏氟乙烯微孔滤膜为支撑膜,绿原酸为模板分子,AM,AA,4-VP,2-VP四种物质分别作为功能单体,用紫外光引发表面修饰聚合制备了绿原酸分子印迹复合膜,测量底物绿原酸在几种印迹膜上吸附量的大小.得出的实验结论和理论计算的结果相一致.Scatchard分析表明,在所研究的浓度范围内分子印迹复合膜中存在两类不同性能的吸附位点,结合位点的平衡离解常数Kd1和Kd2分别为0.151和0.480 mmol/L.底物(绿原酸)的结合和渗透选择性实验表明,分子印迹复合膜对绿原酸有较好的结合性能,结合量分别是14.934和28.123 μmol/g.
展开▼
