氯霉素分子印迹聚合物功能单体筛选及分子识别性能

以氯霉素(CAP)为模板,采用分子动力学和紫外光谱法分析不同功能单体与模板分子间的相互作用情况以辅助筛选单体,并进行实验印证。分子动力学计算出结合能ΔE和紫外光谱最大吸收峰红移程度大小顺序均为甲基丙烯酸(MAA)>丙烯酸(AA)>丙烯酰胺(AM)>甲基丙烯酸甲酯(MMA),且n(MAA):n(CAP)=1:4时MAA与CAP间已有较强的相互作用。由不同功能单体合成的CAP分子印迹聚合物微球(MIPMs)的静态吸附实验表明,在甲醇溶液中,以MAA为功能单体合成的MIPMs对模板CAP的吸附性能最好,饱和吸附量为470.4μmol/g,AA和AM次之,分别为397.5μmol/g和378.3μmol/g,MMA最小,为172.8μmol/g,该结果与分子动力学计算及紫外光谱分析结果相吻合。以MAA为功能单体优化制备MIPMs,SEM显示所得聚合物微球具有良好的单分散性,平均粒径为8.44μm,分散系数为14.2%。最后研究不同用量MAA合成的CAP-MIPMs的分子识别性,实验发现,在各MAA用量下,所得MIPMs对CAP的静态分配系数均高于结构类似物,在n(CAP):n(MAA)=1:4时,其静态分配系数达到111.63 mL/g,CAP与甲砜霉素(TAP)和氟甲砜霉素(FF)间的分离因子分别为4.57和2.78,具有明显的特异识别性。

Synthesis of Functional Monomers Based on Chloramphenicol Molecularly Imprinted Polymers and Their Screening and Molecular Recognition Properties

Molecular dynamics simulations and ultraviolet spectrum(UV) analysis were involved to study the interactions between chloramphenicol(CAP) and different functional monomers by using CAP as a template.The binding energy ΔE and red shift degree of UV maximum absorption peak both followed the order:methacrylic acid(MAA)>acrylic acid(AA)>acrylamide(AM)>methyl methacrylate(MMA).Strong interactions between CAP and MAA were observed when n(MAA):n(CAP)=1:4.Then the adsorption performance of the molecular imprinted polymer microspheres(MIPMs) synthesized by using different functional monomers was studied.The results show that the adsorption performance of MIPMs using MAA as a functional monomer is the best,whose saturation adsorption capacity is 470.4 μmol/g.AA and AM take second place,with about 397.5 μmol/g and 378.3 μmol/g,respectively.The adsorption capacity of MMA-MIPMs is minimum,about 172.8 μmol/g.Based on the experimental results,molecular mechanics calculation and UV analysis,it is indicated that,among the four monomers,MAA is the most suitable functional monomer for CAP.After that,the MIPMs were prepared by using MAA as a functional monomer.Scanning electron microscopy(SEM) shows that the obtained MIPMs had good dispersion with an average size of about 8.44 μm and the dispersion coefficient was determined to be 14.2%.The selectivity of MIPMs prepared with different mole ratio between CAP and MAA was 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,which has the obvious specific identification.In the n(CAP):n(MAA)=1:4 sample,its static distribution coefficient is 111.63 mL/g,while the separation factor between CAP and Thiamphenicol(TAP) and that between CAP and fluorine thiamphenicol(FF) are as high as 4.57 and 2.78,respectively.