Molecularly imprinted polymers on silica: selective supports for high-performance ligand-exchange chromatography.
Molecularly imprinted polymers on silica: selective supports for high-performance ligand-exchange chromatography.
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DOI：
10.1016/0021-9673(95)00378-z
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发表时间：
1995-07
期刊：
影响因子：
--
通讯作者：
S. Plunkett;F. Arnold
中科院分区：
文献类型：
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作者：
S. Plunkett;F. Arnold
薄涂层的分子印迹，金属络合聚合物已接枝到活化的二氧化硅珠适用于高效液相色谱（HPLC）。甲基丙烯酸丙酯活化的二氧化硅颗粒通过与金属螯合单体、Cu 2 +-[N-（4-乙烯基苄基）-亚氨基]糖尿病酸、金属配位（咪唑）模板和乙二醇二甲基丙烯酸酯共聚来涂覆。在提取以去除模板并重新加载金属之后，复合材料重新结合它们所制备的模板，并表现出与本体聚合的印迹材料相当的选择性。强烈的Cu 2 +-咪唑相互作用，期望创建一个高保真的印记，导致过度保留在洗脱色谱。通过用较弱结合的Zn 2+取代印迹金属络合聚合物中的铜，这些新型配体交换支持物可以实现其双咪唑模板与其他高度相似的含咪唑基质的部分至完全色谱分离。这种“诱饵转换”方法可以显着增强分子印迹材料的性能。平衡结合数据的Scatchard图显示在用双咪唑模板制备的材料的印迹结合位点中的显著程度的异质性，但不是用单咪唑模板。最好的色谱分离是在小样品量下观察到的，其中底物占据最强（高保真度）的位点。
Thin coatings of molecularly imprinted, metal-complexing polymers have been grafted to activated silica beads suitable for high-performance liquid chromatography (HPLC). Propylmethacrylate-activated silica particles were coated by copolymerization with a metal-chelating monomer, Cu2+-[N-(4-vinylbenzyl)-imino]diabetic acid, a metal-coordinating (imidazole) template, and ethylene glycol dimethacrylate. After extraction to remove the template and re-loading with metal, the composite materials re-bind the templates with which they were prepared and exhibit selectivities comparable to bulk-polymerized imprinted materials. The strong Cu2+-imidazole interaction, desirable for creating a high-fidelity imprint, leads to excessive retention in elution chromatography. By replacing the copper in the imprinted metal-complexing polymers with weaker-binding Zn2+, these novel ligand-exchange supports can effect partial to complete chromatographic separation of their bis-imidazole templates from other, highly similar imidazole-containing substrates. This “bait-and-switch” approach can significantly enhance the performance of molecularly imprinted materials. Scatchard plots of equilibrium binding data show a significant degree of heterogeneity in the imprinted binding sites of material prepared with a bis-imidazole template, but not with a mono-imidazole template. The best chromatographic separations are observed with small sample sizes, where the substrates occupy the strongest (highest-fidelity) sites.