Alenazi Noof A, Lai Edward P C, Manthorpe Jeffrey M
Department of Chemistry, Carleton University, 1125 Colonel By Drive, Ottawa, ON, K1S 5B6, Canada.
J Mol Recognit. 2014 Dec;27(12):755-62. doi: 10.1002/jmr.2402.
Diazomethane (CH(2)N(2)) was used to methylate the non-specific binding sites after molecularly imprinted polymer particles were prepared using methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the cross-linker and bisphenol A (BPA) as the template. After diazomethane treatment and subsequent removal of BPA by triethylamine, the treated molecularly imprinted polymer (TMIP) particles were tested for binding selectivity toward BPA and other organic compounds by capillary electrophoresis with ultraviolet detection. Even in the presence of compounds that were positively charged, neutral or negatively charged in the background electrolyte, BPA was selectively bound with the highest efficiency. A significant decrease in the affinity for metformin (MF, a positively charged compound), along with (13) C nuclear magnetic resonance spectra and electrophoretic mobility data, provided strong evidence for the elimination of non-specific -COOH binding sites in the TMIP particles. Only 8% of MF and 16% of diclofenac sodium salt (a negatively charged compound) remained as non-specific bindings because of hydrophobic interactions. Further comparison with poly(methyl methacrylate) revealed the true merits of the TMIP, which exhibited minimal non-specific bindings while preserving a high level of specific binding owing to molecular recognition.
以甲基丙烯酸为功能单体、乙二醇二甲基丙烯酸酯为交联剂、双酚A（BPA）为模板制备分子印迹聚合物颗粒后，使用重氮甲烷（CH₂N₂）对非特异性结合位点进行甲基化。在重氮甲烷处理以及随后用三乙胺去除BPA后，通过紫外检测的毛细管电泳对经处理的分子印迹聚合物（TMIP）颗粒针对BPA和其他有机化合物的结合选择性进行了测试。即使在背景电解质中存在带正电、中性或带负电的化合物时，BPA仍能以最高效率被选择性结合。二甲双胍（MF，一种带正电的化合物）亲和力的显著降低，以及¹³C核磁共振光谱和电泳迁移率数据，为消除TMIP颗粒中非特异性-COOH结合位点提供了有力证据。由于疏水相互作用，只有8%的MF和16%的双氯芬酸钠盐（一种带负电的化合物）以非特异性结合形式存在。与聚甲基丙烯酸甲酯的进一步比较揭示了TMIP的真正优势，其非特异性结合极少，同时由于分子识别作用保留了高水平的特异性结合。
