【作者】 陈长宝；

【导师】 周杰；

【作者基本信息】 山东农业大学 ， 应用化学， 2007， 硕士

【摘要】 MIT发展至今已有30多年的历史,它是一种制备对模板分子(又称为印迹分子)具有特异识别MIPs的技术。在TM存在下通过功能单体和交联剂在引发剂的作用下发生自由基聚合制得MIPs母体。当除掉MIPs母体内的TM后就留有与TM在功能基位置、孔穴大小及形状均互补的三维孔穴,即特异识别位点。利用MIPs内所形成孔穴对模板分子的“识别效应”来实现对TM的选择性识别。与抗体和酶等天然的生物识别系统相比,MIPs具有预定的识别性和强的实用性特点。因此,MIPs已经广泛应用于高效液相色谱分离、固相萃取、生物传感器、药物传输系统和仿生膜等领域。虽然MIT近年来发展很快,但是还具有很多的局限性。目前功能单体和交联剂的种类选择范围还比较窄,尤其是功能单体的种类太少以至不能满足某些TM的需求。新型功能单体和交联剂的合成和使用有待于进一步研究开发,以提高MIPs的识别能力、增加结合量和使结合位点更均匀;天然的识别系统大都在水溶液中进行,而现阶段制备的大多数MIPs却只能用于有机溶剂,怎样在极性溶剂或水中较好地制备和应用MIPs还是一个急待解决的问题;目前可被印迹的化合物大部分是小分子化合物,而酶、蛋白质和DNA/RNA等生物大分子化合物的印迹仍然很少。基于此,本文做了如下研究内容:(1)合成了新功能单体9-VA,通过熔点测定、元素分析、FT-IR和1H NMR等分析方法确定了其分子结构;(2)利用分光光度法研究了弱极性溶剂乙腈中功能单体9-VA和植物激素IAA的结合机理。基于此,用IAA作为模板分子,制备了以9-VA为功能单体的MIM。用扫描电镜观测了所制得MIM和NMIM的表面形态;通过单分子渗透实验和多分子竞争扩散实验检验了MIM对IAA、IBA和KT的选择渗透性。测试结果表明:以9-VA为功能单体制备的分子印迹聚合物膜对模板分子IAA的渗透选择性要比对IBA或KT的高。与以MAA为功能单体制备的对照MIM相比,以9-VA为单体制备的MIM对IAA所具有的选择渗透性也比较高。(3)使用光度分析法探讨了功能单体9-VA和模板分子T在甲醇中的结合作用。在此基础上,以DEGDMA为交联剂,纤维素膜为支撑体,制备了MIM。通过扫描电镜观察并比较了MIM、NMIM和纤维素载体膜表面形态的差异,以T、U、C、G和A为底物,评价了MIM的渗透选择性。结果表明MIM对模板分子T及结构最佳类似物U呈现高的选择性。与用EGDMA为交联剂制备的对照分子印迹膜比较,也呈现较高的扩散速率和选择性。更多还原

【Abstract】 Molecularly imprinting technology (MIT) is a method that can prepare molecularly imprinted polymers (MIPs) with specific recognition for template molecule (TM). In the presence of TM, the polymeric reaction occurs by the copolymerization of functional monomers and a cross-linker with an initiator, while the removal of TM in the polymer matrix, three-dimension cavities corresponding to TM in size, shape and functional group are left. Using the recognition effects of MIPs can selectively recognise TM. In comparison with antibody and enzyme in natural bio-recognition system, MIPs have the peculiarities of predeterminate recognition and strong practicability. Hereby, MIPs have been applied to many fields, such as HPLC, SPE, DDS and Bio-mimetic membrane.Although MIT has the fast development in recent years, there are many limitations. At present, the selective range of functional monomers and cross-linkers is better narrow. It is a necessary to synthesize or use novel functional monomers and cross-linkers for improving the recognition ability of MIPs. The recognition on most natural systems is ongoing in water, but now most of MIPs are only polymerized and applied in organic solvent. It is a thoroughly unsolved problem that how to prepare and apply MIPs in polar solvent or water. Now most imprinted compounds are small molecular weight compounds, whereas few of biological macromolecules such as enzyme, protein and DNA/RNA are still imprinted still few.Because of the above-mentioned causes, the following studies are done in this paper.(1) A novel functional monomer 9-vinyladenine (9-VA) was synthesized, its molecular structure was confirmed by melting point measurement, elemental analysis, FT-IR and 1H NMR spectroscopy;(2) The binding mechanism between this functional monomer 9-VA and the plant hormone IAA in acetonitrile was studied with UV-visible spectrophotometeric method. Based on this study, using IAA as TM, a specific 9-VA-based MIM was prepared on cellulose acetate support. Then, the resultant polymeric membrane morphologies were visualized with SEM, and the membrane permselectivity for IAA, IBA and KT was tested with separate experiments and competitive diffusion experiments. These results showed that the MIM prepared with 9-VA as a functional monomer exhibited higher transport selectivity for the template molecule IAA than IBA or KT. The membrane prepared with 9-VA also took on high permselectivity for IAA in comparison with the imprinted membrane made with MAA;(3) The binding mechanism between 9-VA and pyrimidine base T in methanol was studied with spectrophotometric method. Using T as TM, 9-VA as a novel functional monomer and DEGDMA as a new cross-linker, a specific diethylene glycol dimethacrylate-based MIM was prepared over cellulose acetate support. Then, the resultantly polymeric membrane morphologies were visualized with SEM and its permselectivity was examined using T, U, C, A and G as substrates. These results showed that the MIM prepared with DEGDMA exhibited higher transport capacity for the TM thymine and its optimal analog U than other nucleic acid bases. The membrane also took on higher permselectivity than the imprinted membrane made with EGDMA as a cross-linker. When a mixture solution including five nucleic acid bases T, U, C, A, G passed through the DEGDMA-based thymine-imprinted polymeric membrane, the recognition of the imprinted membrane for the template molecule T and its optimal analog U was demonstrated.更多还原