氯霉素分子印迹聚合物合成功能单体筛选及分子识别性能

Study on the Screening of the Functional Monomer for synthesis Chloramphenicol Molecularly Imprinted Polymers and Their Molecular Recognition Characteristics

摘要:

要获得吸附识别性能良好的非共价型分子印迹聚合物，聚合前模板分子与功能单体间的相互作用情况至关重要。本文以氯霉素（CAP）为模板分子，分别以甲基丙烯酸（MAA）、甲基丙烯酸甲酯（MMA）、丙烯酸（AA）和丙烯酰胺（AM）为功能单体，采用分子动力学计算和紫外光谱法研究单体与模板分子间的相互作用情况以筛选单体,并用实验进行印证。分子动力学计算出结合能ΔE的大小顺序为MAA>AA>AM>MMA；紫外光谱中最大吸收峰红移程度的顺序同样为MAA>AA>AM>MMA，且MAA：CAP=1:4（摩尔比）时两者间已有较强的相互作用。静态吸附法测定由各功能单体合成的CAP分子印迹聚合物微球（MIPMs）的饱和吸附量，结果显示：四种功能单体合成的MIPMs对CAP的吸附性能均明显优于相应非印迹聚合物，不同功能单体所得聚合物的饱和吸附量也有显著差异，其大小顺序同样为MAA>AA>AM>MMA。这一结果与分子动力学计算及紫外光谱分析结果相吻合。最后以MAA为功能单体优化制备MIPMs，扫描电镜表明所得聚合物微球具有良好的单分散性，平均粒径为8.44祄，分散系数为14.2%。用静态平衡结合法对不同CAP与MAA比例合成的MIPMs的吸附识别性能进行研究。实验结果表明所制备MIPMs对CAP的静态分配系数明显高于对结构类似物甲砜霉素（TAP）和氟甲砜霉素（FF）的静态分配系数，具有明显的特异识别性。在CAP:MAA=1:4时，CAP与TAP间的分离因子高达4.57。

Abstract:

To obtain the non-covalent molecular imprinted polymer with good adsorption properties, the interaction between the template molecule and functional monomer is importance. Molecular dynamics simulations and ultraviolet spectrum (UV) analysis were made to predict the interactions of the chloramphenicol (CAP) and different functional monomer (methacrylic acid (MAA), acrylicacid (AA), acrylamide (AM), methyl methacrylate (MMA)) complex. Firstly, the binding energy (ΔE) of CAP with different monomers is calculated by using the molecular dynamics method, and the ΔE follows the order of MAA>AA>AM>MMA. Secondly, the interaction strength between CAP and different monomers is studied by ultraviolet spectrum analysis, which is in the same order. Thirdly, the static adsorption experiments of the MIPMs and Non-Imprinted Polymers Microspheres (NIPMs) synthesized by using MAA, AA, AM or MMA respectively are studied, the results show that the adsorption performance of MIPMs for template are obviously better than the corresponding NIPMs, and the saturation adsorption capacity for different functional monomers have significant differences as well, which follows the order: MAA>AA>AM>MMA. Based on the experimental results, molecular mechanics calculation and UV analysis, it indicts that MAA is the most suitable functional monomer for CAP among the four monomers, and the molecular dynamics calculation and UV analysis can be used as effective tools for selecting functional monomer for the synthesis of MIPMs. Finally, molecular imprinted polymer microspheres (MIPMs) were prepared by using MAA as functional monomer. Scanning electron microscopy (SEM) shows that the obtained MIPMs has good dispersion, the average size was 8.44 μm，dispersion coefficient was 14.2%. The selectivity of MIPMs prepared by different molar ratio between CAP and MAA were studied by static adsorption method. The experimental results show that the static adsorption distribution coefficient of CAP is much higher than that of other analogs, has the obvious specific identification. In the CAP:MAA=1:4, the separation factor between CAP and Thiamphenicol (TAP) is as high as 4.57, higher than any other separation factor, this experimental result is consistent with the UV analysis results.