过渡金属氧化物修饰碳糊电极的构筑及在药物分析中的应用

发布时间：2018-02-05 04:39

本文关键词： 碳糊电极氧化钽氧化铌壳聚糖同时检测白杨素黄芩素黄芩苷　出处：《郑州大学》2017年硕士论文　论文类型：学位论文

【摘要】：碳糊电极自从1958年问世以来,就因具有易被修饰、电位窗宽、表面可重复利用率高等独特的优点在电化学领域广受欢迎。其中碳糊电极最有价值的特点就是易被各种水溶性或非水溶性材料修饰。近年来的发展表明,通过金属氧化物粒子修饰碳糊电极受到越来越多电分析工作者的青睐,以绿色、简单易行、灵敏高效等优点著称,通过构筑不同的金属氧化物粒子修饰碳糊电极,辅以电活化、沉积等一些手段,进而筛选最优构筑条件,发挥最大性能,从而实现对药物分子的灵敏检测,最终用于对生物体的的实时监测,研究药物在生物体内的转化关系和速率。基于此,我们借助具有高催化性能的过渡金属氧化物粒子Ta_2O_5和Nb_2O_5及壳聚糖粉末修饰碳糊电极,完成了一系列应用。主要工作如下:(1)首先基于电化学活化Ta_2O_5粒子修饰碳糊电极(EA-Ta_2O_5-CPE)制备了一种新颖的伏安传感器。采用扫描电镜(SEM)、X-射线衍射光谱(XRD)、循环伏安法(CV)和电化学阻抗谱(EIS)对电极的表面结构形态和传感性能进行了表征,实验数据表明该传感器有卓越的电催化性能,对白杨素有良好的伏安响应。随后,采用线性扫描伏安法建立了白杨素的标准曲线,其响应的线性范围为5.0×10~(-7) mol L~(-1)-7.0×10~(-6) mol L~(-1),检出限(S/N=3)为2.0×10~(-8) mol L~(-1)。最后,将建立的方法成功地应用于白杨素胶囊和中草药木蝴蝶中白杨素的含量的测定,结果满意。(2)为进一步提高电极的稳定性和灵敏度,采用直接混合法制备了壳聚糖(CTS)、Ta_2O_5粒子修饰的碳糊电极(Ta_2O_5-CTS-CPE)。通过对电极的组成和操作条件进行系统优化实现了对白杨素和黄芩素的同时检测,构筑电极对白杨素和黄芩素的线性响应范围是8.0×10~(-8) mol L~(-1)-4.0×10~(-6) mol L~(-1),检出限(S/N=3)分别为3.0×10~(-8) mol L~(-1)和5.0×10~(-8) mol L~(-1)。根据实验数据,给出了合理的白杨素和黄芩素在目标电极上的反应机理。同时,测定了中草药木蝴蝶活性成分中白杨素和黄芩素的含量,得到了令人满意的结果。(3)在之前研究的基础上,构筑了双金属氧化物Ta_2O_5-Nb_2O_5复合壳聚糖修饰碳糊电极(Ta_2O_5-Nb_2O_5@CTS-CPE)。Ta_2O_5-Nb_2O_5@CTS-CPE对黄芩素和黄芩苷都有灵敏的响应且可以实现对二者的同时检测。在最佳条件下,采用差分脉冲法建立了黄芩素和黄芩苷的标准曲线,线性范围为8.0×10~(-8) mol L~(-1)至8.0×10~(-6) mol L~(-1),检出限(S/N=3)分别为5.0×10~(-8) mol L~(-1)和3.0×10~(-8) mol L~(-1)。最后,目标电极成功应用于探究生物体内黄芩苷的水解过程和测定中草药黄芩样品中黄芩苷和黄芩素的含量。
[Abstract]:Since the carbon paste electrode was introduced in 1958, it has been easy to be modified and has wide potential window. The unique advantages of high surface repeatability are popular in the electrochemical field. The most valuable characteristic of carbon paste electrode is that it is easy to be modified by a variety of water-soluble or insoluble materials. Recent development shows that carbon paste electrode is easy to be modified by various water-soluble or insoluble materials. Carbon paste electrode modified by metal oxide particles is favored by more and more electrical analysts. It is famous for its advantages such as green, simple, sensitive and efficient. By constructing different metal oxide particles modified carbon paste electrodes, with some means such as electric activation, deposition, and so on, we can select the best construction conditions and give full play to the maximum performance, so as to achieve the sensitive detection of drug molecules. Finally, it is used to monitor the organism in real time, and to study the transformation relationship and rate of drugs in organism. Based on this. Carbon paste electrodes were modified with transition metal oxide particles (Ta_2O_5 and Nb_2O_5) and chitosan powder with high catalytic performance. A series of applications have been completed. The main work is as follows: (1) first of all, the carbon paste electrode modified by Ta_2O_5 particles based on electrochemical activation is used to modify the carbon paste electrode. A novel voltammetry sensor was prepared by scanning electron microscopy (SEM). The surface morphology and sensing properties of the electrode were characterized by X-ray diffraction (XRD), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The experimental data show that the sensor has excellent electrocatalytic performance and good voltammetric response to salicylate. Subsequently, the standard curve of the sensor is established by linear scanning voltammetry. The linear range of its response is 5.0 脳 10 ~ (-7) mol / L ~ (-1) -7.0 脳 10 ~ (-1) mol / L ~ (-1)). The detection limit of S / N ~ (3) is 2.0 脳 10 ~ (-8) mol. The established method has been successfully applied to the determination of the content of aspen in poplar capsules and Chinese herbal medicine. The results are satisfactory. 2) to further improve the stability and sensitivity of the electrode. Chitosan CTS were prepared by direct mixing method. The carbon paste electrode modified by Ta_2O_5 particles was used for the simultaneous detection of Baicalin and baicalin by systematically optimizing the composition and operating conditions of the electrode. The linear response range of the constructed electrode to salicylate and baicalein is 8.0 脳 10 ~ (-8) mol / L ~ (-1) -4.0 脳 10 ~ (-1) mol / L ~ (-1)). The detection limits of S / N ~ (3) were 3.0 脳 10 ~ (-8) mol / L ~ (-1) and 5.0 脳 10 ~ (-8) mol / L ~ (-1), respectively. The reaction mechanism of Baicalin and paeicalin on the target electrode was given. Meanwhile, the contents of salicylin and baicalin in the active components of Chinese herbal medicine were determined. Satisfactory results have been obtained on the basis of previous studies. The carbon paste electrode modified by bimetallic oxide Ta_2O_5-Nb_2O_5 was constructed. Tasp _ 2O5-Nb2O5-CTS-CPE has a sensitive response to both baicalin and baicalin and can be detected simultaneously under the best conditions. The standard curves of baicalin and baicalin were established by differential pulse method. The linear range is 8.0 脳 10 ~ (-8) mol / L ~ (-1) to 8.0 脳 10 ~ (-6) mol / L ~ (-1)). The detection limits of S / N ~ (3) were 5.0 脳 10 ~ (-8) mol / L ~ (-1) and 3.0 脳 10 ~ (-8) mol / L ~ (-1) respectively. The target electrode was successfully used to study the hydrolysis process of baicalin and to determine the content of baicalin and baicalin in the samples of Scutellaria baicalensis.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R917;O657.1

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