【作者】 孟祖超；

【导师】 郑建斌；

【作者基本信息】 西北大学 ， 分析化学， 2012， 博士

【摘要】 随着新型纳米材料的不断涌现及电极修饰方法的不断创新,基于纳米材料的传感研究,特别是无酶电化学传感研究必将展现出显著的发展潜力。本论文基于纳米材料构置了八种无酶电化学传感器,研究了传感器的电化学和电催化行为,建立了测定NO2-、葡萄糖、邻苯二酚、对苯二酚、H2O2及羟胺的电化学分析新方法。该研究丰富了电化学传感器的研究内容,拓展了纳米材料的应用范围。全文共分为四章,作者的主要贡献如下：1、采用电化学沉积法,以MWCNTs为模板,基于CoOx/MWCNTs、ZrO2/MWCNTs和TiO2/MWCNTs等多孔纳米复合材料构置了三种无酶电化学传感器,分别研究了其对NO2-、邻苯二酚和对苯二酚的电催化行为,建立了测定NO2-、邻苯二酚和对苯二酚的电化学分析新方法。实验结果表明,CoOx/MWCNTs和ZrO2/MWCNTs对NO2-均具有良好的催化性能,测定NO2-的线性范围分别为5.0×10-7～2.5×10-4mol·L-1和5.0×10-7～1.1×10-3mol·L-1,检出限均为3.0×10-7mol·L-1(S/N=3)；TiO2/MWCNTs对邻苯二酚和对苯二酚同分异构体具有良好的区分性能及催化性能,测定邻苯二酚的线性范围为1.5×10-63.0×10-4mol·L-1和3.0×104～3.5×10-3mol·L-1,检出限为8.0×10-7mol·L-1(S/N=3)；测定对苯二酚的线性范围为2.5×10-6～2.0×10-4mol·L-1和4.0×104～2.0×10-3mol·L-1,检出限为8.0×10-7mol·L-1(S/N=3).基于这三种多孔纳米材料构置的电化学传感器具有制备简单、灵敏度高和响应速度快等特点。2、通过自组装法,基于Au/Ch、Cu/MnO2和Ag/L-Cys构置了三种无酶电化学传感器,分别研究了其对羟胺、葡萄糖和H2O2的电催化行为及催化机理,建立了测定羟胺、葡萄糖和H2O2的电化学分析新方法。实验结果表明,Au/Ch对羟胺具有良好的催化性能,在1.25×10-6～8.0×10-4mol·L-1的浓度范围,催化氧化峰电流与羟胺浓度呈良好的线性关系,检出限为6.0×10-7mol·L-1(S/N=3)；Cu/MnO2对葡萄糖具有良好的催化性能,测定葡萄糖的线性范围为2.5×10-7-1.02×10-3mol·L-1,检出限为1.0×10-7mol·L-1(S/N=3);Ag/L-Cys对H2O2具有良好的电催化作用,测定H202的线性范围为2.5×10-6-1.5×10-3mol·L-1,检出限为7.0×10-7mol·L-1(S/N=3).通过自组装法构置的这三种电化学传感器具有构造简单、结构易控和线性范围宽的特点。3、通过酶催化反应诱导TmHCF纳米粒子在电极表面生成,建立了测定葡萄糖的电化学分析新方法。研究结果表明,在碳糊电极上通过酶催化反应诱导TmHCF纳米粒子生成时,测得葡萄糖浓度在3.9×10-4～6.2×10-3mol·L-1范围内呈线性关系,检出限为1.0×10-4mol·L-1(S/N=3);在玻碳电极上通过酶催化反应原位合成TmHCF纳米粒子时,测得葡萄糖浓度在2.0×10-5～1.4×10-2mol·L-1范围内呈线性关系,检出限为6.0×10-6mol·L-1(S/N=3)。该研究工作探索了生物催化在电分析化学领域的新应用,为纳米材料合成提供了新思路,为构置新型高灵敏电化学生物传感器提供了参考。更多还原

【Abstract】 With the appearance of new nanomaterials and nanocomposite and the constant innovation of modified methods of electrodes, sensing research based on nanomaterials, especially enzyme-free electrochemical sensing research, shows great potential. In this dissertation, eight kinds of enzyme-free electrochemical sensors were fabricated based on nanomaterials and the electrocatalysis of sensors were investigated in details. The new electrochemical methods for the determination of nitrite, glucose, catechol, hydroquinone, Hydrogen peroxide and hydroxylamine were set up. These results are significant to enrich the research of electrochemical sensors and provide new thoughts for the construction of high sensitive and selective electrochemical sensors. These results also broaden the application range of nanomaterials. The dissertation consists of four chapters. The author’s main contributions are summarized and presented as follows:1. By electrodeposition in which MWCNTs were used as template, three kinds of enzyme-free electrochemical sensors based on porous CoOx/MWCNTs, ZrO2/MWCNTs, TiO2/MWCNTs nanocomposite were fabricated and their electrocatalytic behaviors were investigated, respectively. The corresponding electrochemical methods were presented for the determination of NO2-, catechol and hydroquinone, respectively. The experimental results indicated that CoOx/MWCNTs and ZrO2/MWCNTs showed excellent electrocatalytic activity toward the oxidation of nitrite. The linear range for the determination of nitrite were found to be5.0×10-7～2.5×10-4mol·L-1and5.0×10-7～1.1×10-3mol·L-1, respectively. And the detection limit was3.0×10-7mol·L-1(S/N=3). TiO2/MWCNTs can distinguish between catechol and hydroquinone, and showed excellent catalytic properties toward the oxidation of catechol and hydroquinone. The linear range for the determination of catechol and hydroquinone were found to be1.5×10-6～3.0×10-4mol·L-1and3.0×10-4～3.5×10-3mol·L-1. The linear range for the determination of hydroquinone were2.5×10-6mol·L-1～2.0×10-4mol·L-1and4.0×10-4mol·L-1～2.0×10-3mol·L-1.And the detection limit was8.0×10-7mol·L-1(S/N=3). The electrochemical sensors based on the three porous nanomaterials indicated these characteristics of simple preparation, high sensitivity and fast response, which were mainly because large specific surface area of porous nanocomposite can promote electronic transfer and improve the catalytic performance of nanocomposite.2. By electrodeposition and self-assembly, three kinds of enzyme-free electrochemical sensors based on Au/Ch, Cu/MnO2and Ag/L-Cys were fabricated and their electrocatalytic behaviors were investigated. The new electrochemical methods were presented for the determination of hydroxylamine, glucose, H2O2. The experimental results indicated that Au/Ch showed excellent electrocatalytic activity toward the oxidation of hydroxylamine. The linear range for the determination of hydroxylamine was found to be1.3×10-6～8.0×10-4mol·L-1and the detection limit was6.0×10-7mol·L-1(S/N=3). Cu/MnO2exhibited excellent electrocatalytic activity toward the oxidation of glucose. The oxidation peak current had a linear relationship with the concentration of glucose in the range from2.5×107mol·L-1to1.0×10-3mol·L-1with a very low detection limit of1.0×10-7mol·L-1(S/N=3). Ag/L-Cys showed excellent electrocatalytic activities toward the reduction of H2O2with the linear range of2.5×10-6mol·L-1to1.5×10-3mol·L-1. The detection limits were7.0×10-7mol·L-1(S/N=3). The three electrochemical sensor based on self-assembly have the advantages of simple structure, flexible control and good stability.3. The formation of Thulium (Ⅲ) hexacyanoferrate (Ⅱ)(TmHCF) nanoparticles induced by enzymatic reaction on the surface of carbon-paste electrode (CPE) and GOx-CHIT/GCE was described and characterized. The new electrochemical methods were presented for the determination of glucose. The experimental results indicated that the linear relationship between current response of TmHCF and glucose concentration were3.9×10-4～7.0mol·L-1and2.0×10-5～1.4×10-2mol·L-1, respectively. These research explore new application of the biological catalysis in electroanalytical chemistry, offer new ideas for the synthesis of nanomaterials, and provide a general platform for the construction of electrochemical biosensors.更多还原