【作者】 王丽兰；

【导师】 傅英姿；

【作者基本信息】 西南大学 ， 分析化学， 2011， 硕士

【摘要】 电化学手性分析是电化学分析技术和手性识别方法的有机结合,根据电化学响应信号差异进行手性识别研究,具备了电化学方法的高灵敏、响应快、低成本,易于智能化和微型化等优点,同时还具备了手性识别方法的立体对映选择性,在医学及药学、食品安全、农业化学药品应用和环境安全检测等研究领域具有重要的研究意义。本文在国内外手性识别研究基础上,利用氮氧小分子构建手性电极表面,探讨了手性表面与生物分子和药物中间体的手性识别作用,主要研究工作如下：1.研究了DNA分子在1,2-二苯基乙二胺(DPEN)对映异构体构建的手性表面上的立体选择性吸附作用。通过共价键合将(1R,2R)-或(1S,2S)-DPEN修饰到金基底电极上形成手性表面。采用循环伏安技术表征并研究了手性表面的修饰过程及其电化学性质。通过原子力显微技术、循环伏安、电化学交流阻抗和石英晶体微天平技术分别研究了DNA分子在两种手性表面上的立体选择性吸附行为。实验结果表明,(1R,2R)-DPEN手性表面与DNA分子的作用强于(1S,2S)-DPEN手性表面,表面的手性对DNA分子的形态及吸附量产生了不同的影响。2.研究了L-半胱氨酸修饰的金电极(L-Cys-Au),在Zn(II)存在下对药物中间体扁桃酸(MA)对映异构体的手性识别作用。通过循环伏安和电化学交流阻抗技术研究发现,在Zn(II)存在下,L-Cys-Au与R-MA溶液反应后的电化学响应明显强于S-MA溶液,且Zn(II)是导致该手性识别的重要因素：L-Cys与MA对映异构体选择性形成锌金属配合物。利用该法制备的手性传感器能够简便、快速地识别不同构型的MA分子,且能检测MA对映异构体比例,进一步扩展了手性配体交换原理在类氨基酸物质中的应用。3.采用电化学聚合方法在玻碳电极表面制备了L-氨甲喋吟(L-Mtx)手性聚合膜,并采用差分脉冲和循环伏安技术,在优化的聚合条件下研究了该手性聚合膜的相关电化学性质。对比研究发现,在相同条件下,聚合膜的氧化峰电流和还原峰电流明显大于L-Mtx溶液,其值是L-Mtx溶液峰值的15倍左右。但实验表明L-Mtx聚合膜的电化学性质是不可逆的。该手性聚合膜的制备和性质研究为其在手性识别中的进一步应用研究打下了良好的实验基础。更多还原

【Abstract】 Electrochemical chiral analysis combines electrochemical analytical technique and chiral recognition. The investigation of chiral recognition was based on the different responses of electrochemical signals. This analysis method possess the merits of electrochemical method, for example, high selectivity, quick response, lower cost, easy intelligentification and micromation, meanwhile, has the high steroselectivity of chiral recognition. Thus, electrochemical chiral analysis methods display great potential applications in the pharmacy and medicine industries, food safety, agrochemical applications and natural environment protection. Based on the current situation and significance of chiral investigation, chiral nitrogen-oxygen molecules were used to construct the chiral surfaces by different methods in our works. And these chiral surfaces were further investigated in the biomolecular recognition and chiral sensors by electrochemical methods.1. This work described an interesting phenomenon of the stereoselective adsorption behaviors of DNA on stable chiral surfaces which were modified with 1, 2-diphenylethylenediamine enantiomers on gold electrodes. The modification process and electrochemical characterization of the chiral surfaces were measured by cyclic voltammetry (CV). The stereoselective adsorption behaviors of DNA on the two chiral surfaces were investigated via atomic force microscopy (AFM), CV, electrochemical impedance spectroscopy (EIS) and quartz crystal microbalance (QCM). All results confirmed that (1R,2R)-1,2-diphenylethylenediamine modified surface had stronger interaction with DNA molecules than (1S,2S)-1,2-diphenylethylenediamine modified surface, and the chirality of the surfaces created an different effect on the morphology and adsorption quantity of DNA.2. An obviously enantioselective strategy for the recognition of mandelic acid (MA) enantiomers in the presence of Zn(Ⅱ) ions on a L-cysteine (L-Cys) self-assembled gold electrode is described. The high recognition of MA was evaluated via electrochemical impedance spectroscopy and cyclic voltammetry. After the modified electrode interacted with R-or S-MA solution containing Zn(II) ions for 10 min, larger electrochemical response signals were observed for R-MA. Time dependencies of the enantioselective interaction for the modified electrode with the solitary Zn (Ⅱ) solution and MA enantiomers solutions containing Zn(II) were also investigated. The results showed that the enantioselective recognition was caused by the selective formation of Zn complex with L-Cys and MA enantiomers. In addition, the enantiomeric composition of R-and S-MA enantiomer mixtures could be monitored by measuring the current responses of the sample.3. In this part, a novel chiral film electrode was constructed based on electropolymerization of L-methotrexate on a glassy carbon electrode. The electrochemical properties of this chiral film were investigatied via cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The condition of electropolymerization was optimized by DPV. In a certain potential range, the chiral film showed good electrochemical activity. However, the L-methotrexate solution has weak electrochemical activity on the bare glassy carbon electrode. The current values of the chiral film were obviously larger than that of L-methotrexate solution. The work will offer valuable reference to the further studies of this chiral film electrode in chiral recognition, especially in chiral catalysis.更多还原