毒死蜱分子印迹聚合物微球的制备及结合特性的研究

采用无皂乳液聚合法制得的微米级聚苯乙烯微球为种球，以毒死蜱为模板分子，通过单步溶胀聚合法制备了单分散分子印迹聚合物微球（MIPMs）。通过紫外光谱研究了MIPMs的结合机理和识别特性；利用红外光谱分析MIPMs的结合位点；运用扫描电子显微镜对微球进行形貌分析，MIPMs的粒径分布为0.5～3 μm（UMIPMs为2～3 μm），其表面粗糙具有一定层次孔径分布的多孔性聚合物，有利于底物和结合位点的接触，从而获得高负载量和高效识别性；Scatchard 分析表明MIPMs在识别毒死蜱过程中存在两类结合位点，计算得高亲和性位点的解离常数为 KD1 = 0.526 mmol/L，最大表观结合量Bmax1 = 35.91 μmol/ g，低亲和位点的解离常数为 KD2 = 2.19 mmol/L，最大表观结合量Bmax1 = 83.87 μmol/g。

Synthesis and Characterization of Molecularly Imprinted Polymer Microspheres for Recognition of Chlorpyrifos

Molecularly imprinted polymeric microspheres(MIPMs) were prepared by a one-step swelling polymerization method in an aqueous system with polystyrene microspheres obtained by emulsifer-free polyme-rization as seeds and Chlorpyrifos as template molecules. The selective binding characteristics of the MIPMs were evaluated by ultraviolet spectrometry. The infrared spectrum(IR) of the polymer further indicated that there were some functional groups in the moleculary imprinted polymer which could interact with the template. Subsequent morphological characterization of the MIPMs by means of scanning electron microscopy(SEM) shows that the diameters were between 0.5～3 μm(2～3 μm for UMIPMs), and surface rugosity and high porosity facilitated the approaching of the template to the binding sites, so as to obtain high load, affinity and selectivity for the template molecules. Scatchard analysis suggests that during MIPMs recognition of Chlorpyrifos, there were two classes of binding sites. The calculated dissociation constant K_(D1) and apparent maximum number B_(max1) of binding sites with high affinity were 0.526 mmol/L and 35.91 μmol/g respectively, while K_(D2) and B_(max2) of binding sites with low affinity were 2.19 mmol/L and 83.87 μmol/g.