【作者】 刘洁；

【导师】 冶保献；

【作者基本信息】 郑州大学 ， 环境科学， 2014， 硕士

【摘要】 自问世以来，化学修饰电极一直活跃在电化学和电分析化学的前沿领域。电极修饰材料在化学修饰电极研究中起着重要的作用，一直以来都是研究的热点。其中碳纳米管和氨基酸聚合物类修饰材料凭借着其自身独特的性质，得到了电化学工作者的广泛关注。碳纳米管本身导电性高、比表面积大，另外还具有优越的电催化活性、良好的化学稳定性，应用于化学传感器中能够对某些物质的电化学行为产生特定的催化效应。聚合物修饰电极也凭借着制备简单、电极寿命长、膜与基底电极连接牢固等一系列优点，在电分析化学中倍受青睐。鉴于此研究背景，本论文以碳纳米管和氨基酸聚合物为修饰材料，构筑了几种伏安传感器用于一些小分子灵敏快捷的测定。主要研究工作如下：1.利用电化学聚合的方法制备了一种简单可靠的聚DL-天冬氨酸伏安传感器，研究了马钱子碱在该电极上的电化学特性。在最佳的实验条件下，测定马钱子碱的线性范围：5.0×10-8mol L-1~9.0×10-5mol L-1，检出限达到3×10-8mol L-1。并求得了电极反应动力学参数，对电极反应机理进行了合理地探讨。2.利用滴涂的方法制备了一种灵敏、快速、低成本的多壁碳纳米管（MWCNTs）复合Nafion膜修饰电极，用以对中草药陈皮中的辛弗林的痕量检测。在B-R缓冲溶液中，采用循环伏安法研究了辛弗林在该传感器上的电化学行为，是一个两电子参与、受吸附控制、不可逆的电极反应过程。在最佳实验条件下，峰电流与辛弗林浓度1×10-8~1×10-5mol L-1范围内呈线性关系，检出限为8×10-9mol L-1。实验进一步研究了不同pH值和扫率对辛弗林响应的影响，结合紫外可见光谱法推断了辛弗林电化学反应机理。另外，将该电极应用于中草药陈皮中的辛弗林的检测，结果令人满意。3.先在电极表面聚合一层天冬氨酸膜（Asp），再用滴涂的方式将MWCNTs固定在其表面，从而制备了一种MWCNTs/Asp/GCE的新型伏安传感器用于测定杀虫剂吡虫啉。MWCNTs和聚合物的协同效应显著提高了吡虫啉的在该修饰电极上的电化学响应。在最佳条件下，线性范围为：6.0×10-8mol L-1~6.0×10-5molL-1，检出限为：4.5×10-8mol L-1。该传感器具有表面易更新，重现性、稳定性良好等优势。同时证明了方法在复杂环境样品中的实用性。更多还原

【Abstract】 Chemically modified electrodes have been active in the forefront ofelectrochemistry and electroanalytical chemistry field. The modified material plays animportant role in this field. As always, it has attracted more and more attention.MWCNTs and amino acid polymer have gotten extensive application byelectrochemical workers depending on their own unique properties. The MWCNTspossesses the advantage of good electric conductivity, large surface area,electrocatalytic performance and good chemical stability. Based on sensorapplications, it could produce specific catalytic effect to the electrochemical behaviorof analytes. Polymer film also has attracted lots of attention with a series of meritssuch as simple preparation, long service life, diverse methods, strong connectionbetween membrane and the base electrode. In view of this background, the MWCNTsand polyaminoacid material were used as the main modifier in this thesis. Based onthis, three kind of voltammetric sensors were fabricated and used for sensitive andfast determination of some useful small molecule materials. The main research areexpressed as follows:1. A simple and reliable electrochemical sensor based on poly(DL-Aspartic acid)modified glassy carbon electrode was proposed for direct determination of brucine.The electrochemical characters of brucine on this sensor was carefully andsystematically studied by cyclic voltammetry. Some kinetics parameters werecalculated and a reasonable reaction mechanism of brucine at the poly(DL-Asparticacid)/GCE was also proposed. Meanwhile, a new electroanalytical method fordetermination of brucine was proposed with highly sensitive detection limit of3×10-8mol L-1(S/N=3) and wide linear range of5.0×10-8mol L-1to9.0×10-5mol L-1.2. A sensitive, fast and cheap voltammetric sensor for quantitative determinationof synephrine in Chinese traditional herbal drug pericarpium citri reticulatae usingglassy carbon electrode (GCE) based on MWCNTs-Nafion film was reported. Theelectrochemical behavior of synephrine on this sensor was explored inBritton-Robinson buffer solution using cyclic voltammetric technique. Moreover, cyclic voltammetric studies indicated that the oxidation of synephrine at the modifiedelectrode was irreversible, adsorption controlled and involved two electrons. Linearcalibration plot between the oxidation peak current and the synephrine concentrationwas in the range of1×10-8to1×10-5mol L-1. Detection limit of synephrine was foundto be8×10-9mol L-1by linear sweep voltammetry technique. Besides, the analyticalperformance of this sensor was evaluated for the detection of synephrine in realsamples.3. A new voltammetric sensor, based on multi-walled carbon nanotubes(MWCNTs) composite poly(aspartic acid) film modified glassy carbon electrode, wasfabricated and used for determination of pesticide imidacloprid. The synergistic effectof MWCNTs and the polymer resulted in a significantly improved electrochemicalresponse of imidacloprid. Under selective conditions, the detect linear range was from6.0×10-8mol L-1upto6.0×10-5mol L-1with a detection limit of4.5×10-8mol L-1. Thesensor also had an easily renewable surface, good fabrication reproducibility, andinherent stability. Moreover, satisfactory results were obtained with complexenvironmental samples and demonstrate the reliability of the method.更多还原