【作者】 喻来波；

【导师】 吴健玲； 李利军；

【作者基本信息】 广西大学 ， 分析化学， 2008， 硕士

【摘要】 论文从方法、原理及性能等方面对化学修饰电极的设计、表征及催化效能进行了论述。并将其应用于构建流动注射不可逆双安培分析,对化学修饰电极中的自组装修饰、电聚合修饰及纳米粒子的接附修饰三类电极的设计进行了探讨,并对其在电化学催化氧化、电流增敏等应用机理进行了理论研究。其具体研究内容如下:1.利用S-Au键的强相互作用,在裸金电极上制备了L-半胱氨酸自组装膜金修饰电极（L-Cys/SAM-Au/CME）,研究了阿魏酸在其上的电化学行为。将自组装膜修饰电极用于流动注射不可逆双安培（FI-IB）体系的构建,利用阿魏酸在L-Cys/SAM-Au/CME上的氧化和高锰酸钾（KMnO₄）在裸金电极上的还原构建双安培检测新体系。氧化峰峰电流与阿魏酸浓度在5.0×10^-7～8.0×10^-5mol/L范围内呈线性关系,其线性回归方程为i（nA）=4.16×10⁷ C+50,在1.0×10^-4～1.0×10^-3mol/L范围内呈线性关系,其线性回归方程为i（nA）=5.6×10⁶ C+300,检出限为1.2×10^-7mol/L,并应用于阿魏酸钠盐注射液中阿魏酸的测定,结果满意。2.在N,N-二环已基碳酰亚胺（DCC）存在介质下,通过酰氨键使多壁碳纳米管（MWCNTs）与L-半胱氨酸（L-Cys）缩合,功能化的MWCNTs通过结构中的S-Au键自组装接着于金电极表面,制备MWCNTs-L-Cys-Au/SAMs-CME,实现了对金电极的MWCNTs、L-Cys共组装修饰,并对其结构进行谱学与电化学表征。探讨了其对Rev的电催化氧化机理。氧化峰峰电流与白藜芦醇浓度在1.0×10^-5～2.0×10^-7mol/L范围内呈线性关系,其线性回归方程为i（nA）=2.57×10⁶C-260,在2.0×10^-3～2.0×10^-5mol/L范围内呈线性关系,其线性回归方程为i（nA）=1.65×10⁷ C-420,方法检出限为8.0×10^-8mol/L。该方法具有较高的选择性和灵敏度、样品处理方法简单快速。测定了虎杖及葡萄酒中Rev的含量,结果满意。3.利用循环伏安法（CV法）将单体L-苏氨酸（Lry）在铅笔芯电极循环聚合,以形成导电性聚合物修饰膜（P-Lry）,探讨了铅笔芯修饰电极上的最佳聚合条件,并对其进行微观显象表征。研究了药物盐酸异丙嗪在该修饰电极上的电化学行为。在pH 6.8磷酸盐缓冲溶液（PBS）中,该氧化峰峰电流（ipa）与盐酸异丙嗪浓度在2.0×10^-6～1.5×10^-3mol/L范围内呈线性关系,方法检出限为8.5×10^-7mol/L（S/N=3）。对盐酸异丙嗪片剂测定结果满意。4.在玻碳电极基底上成功的制备了MWCNTs修饰电极（MWCNTs/GCE-CME）,并对其表面结构进行显微表征。研究了双嘧达莫（DPD）在该修饰电极上的电化学行为及多种表面活性剂对DPD在MWCNTs/GCE-CME的影响。尝试提出MWCNTs对药物分析中的电催化氧化机理的推论。将包含有MWCNTs的MWCNTs/GCE-CME应用于FI-IB体系的构建,建立了在SDS介质下,直接测定DPD的新方法。在0.05 mol/L H₂SO₄介质溶液中,其ipa与DPD浓度在1.0×10^-3～1.5×10^-6mol/L范围内呈线性关系,方法检出限为8.0×10^-7mol/L。该方法对双嘧达莫片剂测定结果满意。更多还原

【Abstract】 The study on the methods,principles and performance aspects of the chemically modified electrodes which contain designing,characterization and catalytic efficiency are discussed.In this paper,we construct and design the three types of chemically modified electrodes,apply to flow injection-irreversible biamperometric with the self-assembly modification,polymer modification,and access of nanoparticles modification.The mechanism of electrocatalysis oxidation to analysis material on modified electrode was studied.We take the theoretical investigation about oxidation current increases significantly under the effect of enhancement of electrc transfer at modified electrode comparison to that at the bare electrode.Its specific research as follows:1.L-cysteine self-assembled monolayers has been fabricated on the surface of gold electrode（L-Cys/SAM-Au/CME）by S-Au bond interaction,also the electrochemical behaviors of ferulic acid on the modified electrode were investigated.The method of self-assembled monolayers modified electrode is applied to establish in the flow-injection irreversible biamperometric analysis,the irreversible system is composed of electro-catalytic oxidation of ferulic acid on L-cysteine gold modified electrode and reduction of permanganate at the other bare gold electrode.The oxidative peak current increases linearly with the concentration of ferulic acid in the range of 5.0×10^-7～8.0×10^-5mol/L,linear regression equation:i（nA）=4.16×10⁷ C+ 50,and in the range of 1.0×10^-4～1.0×10^-3mol/L, linear regression equation:i（nA）=5.6×10⁶ C+300.The detection limit for ferulic acid is 1.2×10^-7mol/L.This proposed method was applied to the analysis of sodium ferulate injection with satisfactory results.2.With the aid of a condensation agent DCC,the open-ended and carboxyl groups terminated MWCNTs（multi-walled carbon nanotubes）and L-Cys（L-cysteine）condensation reaction through the carboxyl and amino group,and the function of MWCNTs form self-assembled monolayers on gold electrode surface via bond of S-Au.Prepare the modified electrode of MCNTs-L-Cys-Au/SAMs by co-assembling on gold electrode surface with MWCNTs and L-Cys.Meanwhile,we take the investigation of optical spectroscopy and electrochemistry for modified electrode.Meantime,the mechanism of electrocatalysis oxidation to resveratrol on modified electrode was studied.The oxidative peak current increases linearly with the concentration of resveratrol in the range of 1.0×10^-5～2.0×10^-7 mol/L,linear regression equation:i（nA）=2.57×10⁶ C-260,and in the range of 2.0×10^-3～8.0×10^-5mol/L,linear regression equation:i（nA）=1.57×107C-420.The detection limit for resveratrol is 8.0×10^-8mol/L.This proposed method has the advantage of high selectivity and sensitivity.The disposal method of the sample is simple,and applied to the analysis of resveratrol in giant knotweed and red wine with satisfactory results.3.The Poly（L-threonine）modified electrode is prepared successfully by using cyclic voltammetric method at lead electrode.The optimum polymerization condition of L-threonine on lead electrode is studied,and the microscopic configuration of the surface of modified electrode also is characterized.The electrochemical behaviors of promethazine on the poly（L-threonine）lead modified electrode are studied.In pH 6.8 phosphate buffer solution （PBS）,the oxidative peak current increases linearly with the concentration of promethazine in the range of 2.0×10^-6～1.5×10^-3mol/L,linear regression equation:i（nA）=1.97×10⁷ C-300. The detection limit for promethazine is 8.5×10^-7mol/L.This proposed method is applied to the analysis of promethazine tablet with satisfactory results.4.The multi-wall carbon nanotubes-modified glassy-carbon electrode（MWCNTs /GCE-CME）is prepared at the bare glassy-carbon electrode,and the micrographs of the MWCNTs/GCE-CME are obtained by device of scanning electron microscopy.The electrochemical behaviors of dipyridamole（DPD）on the modified electrode are studied.The oxidation peak current of DPD at the MWCNTs/GCE-CME under the effect of enhancement of surfactant are investigated.The mechanism is investigated.The oxidative peak current increases linearly with the concentration of DPD in the range of 1.5×10^-6～1.0×10^-3mol/L, linear regression equation:i（nA）=2.37×10⁶ C-450.The detection limit for DPD is 8.0×10^-7 mol/L.This proposed method was applied to the analysis of DPD tablet with satisfactory results by using MWCNTs/GCE-CME.更多还原