基于石墨烯及 PEDOT 的电活性化合物检测方法及机制研究

发布时间：2018-02-23 07:20

本文关键词： 聚(3 4-乙烯二氧噻吩) 石墨烯电活性化合物电化学分析同时检测　出处：《天津理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：多巴胺(DA)、尿酸(UA)、酪氨酸(Tyr)、氢氯噻嗪(HCTZ)为常见的电活性物质,本文开发一种新颖的石墨烯基电化学传感器研究了同时化验微量DA、UA、Tyr和HCTZ的分析方法和机制。石墨烯/钽(Ta)电极作为传感电极采用电化学分析方法中的差分脉冲伏安法可以同时测定DA、UA、Tyr及HCTZ。采用该方法同时测定DA、UA、Tyr及HCTZ时,邻近分析物之间的最小峰电位差为0.132 V(DA和UA)最大达到0.28 V(UA和Tyr)。DA、UA、Tyr和HCTZ四种物质的检测线性范围依次为0.3-40μΜ,0.3-400μΜ,3-800μΜ,0.5-500μΜ,检测限分别为0.04μΜ、0.1μΜ、0.6μΜ和0.4μΜ。这些结果表明,石墨烯/Ta电极是一种很有前途的电化学传感器并且具有灵敏度高、选择性和稳定性好的优势。检测电极石墨烯层的特征可以通过电子扫描电镜(SEM)、透射电子显微镜(TEM)、X射线衍射(XRD)、电化学阻抗(EIS)和循环伏安法(CV)方法对检测电极的石墨烯层的特征进行了分析。石墨烯通过直流等离子体化学气相沉积方法垂直生长在Ta基片上。石墨烯作为敏感材料,其具有大的有效活性表面积,高导电性和大量的电催化活性位点,于是可以分辨上述四种化合物且实现同步定量分析。苯二酚具有三种同分异构体包括对苯二酚(HQ)、邻苯二酚(CC)和间苯二酚(RC),而传统的检测方法难以区分它们。我们以3,4-乙烯二氧噻吩为单体,采用电化学的循环伏安法在石墨烯表面原位聚合了聚(3,4-乙烯二氧噻吩)导电聚合物层(PEDOT),最终制备出一维PEDOT/石墨烯复合的传感电极。一维PEDOT结构的直径约200 nm,长度可以达到几微米。PEDOT/石墨烯传感电极可以区分HQ、CC、RC和亚硝酸盐。HQ、CC、RC及亚硝酸根的峰电位分别位于12 m V、120 mV、512 mV及700 mV处,峰电位差均超过100 mV,检测限分别是0.06μM、0.04μM、0.15μM、和5μM。PEDOT/石墨烯传感电极具有电催化活性和选择性高,检测速度快,使用寿命长的优势。这是因为微纳尺寸的一维形态贡献了大的比表面,而聚合物-石墨烯杂化结构生成了独特的电学性能及化学稳定性。
[Abstract]:Dopamine (DA), uric acid (UAA), tyrosine tyrosine (Tyr), hydrochlorothiazide (HCTZ) are common electroactive substances. In this paper, a novel graphene based electrochemical sensor has been developed to study the analytical method and mechanism of simultaneous detection of trace amounts of DAA UAA Tyr and HCTZ. The graphene / tantalum Taa electrode is used as the sensing electrode and the differential pulse volt in the electrochemical analysis method is used. The method can be used to determine the Tyr and HCTZ simultaneously. When using this method, the Tyr and HCTZ of the UAA can be determined at the same time. The minimum peak potential difference between the adjacent analytes is 0.132V / L DA and UAA). The linear range of detection for the four substances is 0.28 V ~ (-1) and 0.28 渭渭渭 m ~ (-1) and 0.3-40 渭渭渭 ~ (-400) 渭渭渭 ~ (-800) 渭渭渭 ~ (-500) 渭渭渭 m, respectively, and the detection limits are 0.04 渭渭渭 ~ (0.1) 渭渭渭 ~ (0.6 渭) and 0.4 渭 ~ (渭) 渭 m, respectively. The results show that, Graphene / Ta electrode is a promising electrochemical sensor with high sensitivity. The advantages of selectivity and stability. The characteristics of graphene layer can be detected by means of electron scanning electron microscopy (SEM), transmission electron microscope (TEM), Tem X ray diffraction (XRD), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) to detect the graphite of the electrode by means of electron scanning electron microscope (SEM), transmission electron microscope (TEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The characteristics of the alkene layer were analyzed. Graphene was grown vertically on Ta substrate by direct current plasma chemical vapor deposition. Graphene was used as sensitive material. It has large active surface area, high conductivity and a large number of electrocatalytic active sites. It is possible to distinguish the four compounds and to achieve simultaneous quantitative analysis. There are three isomers of dihydroxybenzene, including hydroquinone, catechol (CCC) and resorcinol (RCN), which are difficult to be distinguished by traditional methods. In this paper, the monomer of 3C4- ethylenedioxothiophene was used as monomer. In situ polymerization of PEDOTN on the surface of graphene by electrochemical cyclic voltammetry was carried out. Finally, a one-dimensional PEDOT / graphene composite sensing electrode was prepared. The diameter and length of one-dimensional PEDOT structure were about 200nm. A few micron PEDOT / graphene sensing electrode can be used to distinguish the peak potentials of HQC CCRC and nitrite. HQN CCN RC and nitrite at 12mV, 120mV 512mV and 700mV, respectively. The peak potential difference is more than 100 MV, and the detection limit is 0.06 渭 M ~ 0.04 渭 M ~ (-1) 0.15 渭 M, respectively, and 5 渭 M. PEDOT / graphene sensing electrode has the advantages of high electrocatalytic activity and selectivity, high detection speed and long service life. The hybrid structure of polymer-graphene resulted in unique electrical properties and chemical stability.
【学位授予单位】：天津理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O657.1;TP212

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