基于五种功能纳米材料的电化学传感器的构置及其应用

【作者】 王琦；

【导师】 郑建斌；

【作者基本信息】 西北大学 ， 分析化学， 2011， 博士

【摘要】 开发新型功能纳米材料和复合材料并将其用于构置高灵敏、高选择性的电化学传感器及其应用的研究是当今分析化学的热点研究方向之一。本论文采用电化学方法制备了五种功能纳米材料和复合材料并利用其构置了新型的电化学传感器,研究了传感器的电化学行为,建立了H202、HCHO和N2H4等六种物质的伏安分析新方法。该研究为研制高灵敏、高选择性的电化学传感器提供了新材料、新思路,拓展了纳米材料及其复合材料的应用范围。全文共分五章,作者的主要贡献如下：1、构置了基于AgPd合金纳米粒子的新型甲醛传感器和基于PdNi合金纳米粒子的新型肼传感器,研究了其电化学和电催化特性,建立了HCHO和N2H4的伏安分析新方法。结果表明,前者实现了对甲醛的灵敏测定,线性范围为0.060mM-20mM,检出限为0.022mM。后者实现了对肼的灵敏测定,线性范围为1μM-2.1 mM,检出限为0.32gM。构置的甲醛传感器具有灵敏度高、选择性好、抗CO中毒的特性；肼传感器具有灵敏度高、稳定性好的特点,尤其是大大降低了电催化氧化N2H4的过电位。2、采用脉冲电沉积法制备了Ag NPs/ZnO复合物,研究了Ag NPs/ZnO复合物的电化学性质及其对H2O2的电催化作用；以离子液体(BMIM·PF6)为溶剂制备了PANI/SWCNTs复合物,研究了PANI/SWCNTs复合物的电化学性质及其对H2O2的电催化作用,并在此基础上构置了两种无酶H2O2传感器。结果表明,两者均实现了对H2O2的灵敏测定,前者的线性范围为2μM-5.5mM,检出限为0.42μM；后者的线性范围为5μM-1mM,检出限为1.2μM。前者具有灵敏度高的特点,后者具有选择性好的特点。3、构置了HRP-SWCNTs-HA/GCE和Hb-HAp-GE/GCE修饰电极,研究了HRP和Hb在复合膜修饰电极上的直接电化学行为和电催化性质,并建立了伏安法测定H202的新方法。研究表明,SWCNTs-HA复合膜和HAp-GE复合膜能实现HRP和Hb在电极表面的直接电子转移,且两种修饰电极对H202表现出良好的电催化作用。可见,HAp-GE和SWCNTs-HA纳米复合材料能够显著提高氧化还原蛋白质(酶)的直接电子传递速率且具有良好的生物相容性。4、构置了基于AgHCF-PEDOT-GE三元纳米复合物的新型多功能的电化学传感器,研究了其电化学和电催化特性,建立了同时测定AA.DA和UA的伏安分析新方法。研究表明,AgHCF-PEDOT-GE三元纳米复合物对AA.DA和UA具有良好的电催化活性,测定AA.DA和UA的线性范围分别为1-2000μM、2-500μM和0.8-500μM,灵敏度分别为0.13、0.60和0.28μAμM-1,检出限分别为0.25μM、0.1μM和0.08μM。该传感器的线性范围宽且能提供低电位检测。更多还原

【Abstract】 Using new materials, including nanomaterials, and composite materials in construction of high sensitive and selective electrochemical sensor has already been active area of modern analytical chemistry study. In this thesis, five kinds of new electrochemical sensors based on nanomaterials and composite materials are fabricated, after which the electrochemical behaviors are studied in details. The new voltammetric analytical methods for H2O2, HCHO, N2H4, AA, DA and UA are set up. These studies may provide new thoughts for the construction of high sensitive and selective electrochemical sensor and broadens the application range of nanomaterials and composite materials. The thesis consists of five chapters and the author’s main contributions are as follows:1. Two electrochemical sensor ultalizing alloy nanoparticles are proposed. The former is based on the electrodeposition of AgPd alloy nanoparticles on chitosan(Ch)-ionic liquid gel film. The latter is based on the electrodeposition of PdNi alloy nanoparticles on chitosan(PEDOT)-graphene (GE) composite film. The electrochemistry and electrocatalysis of two sensors are investigated, and then new methods for HCHO and N2H4 determination are established. The research shows that the former exhibits a significant electrocatalytic activity toward HCHO. The oxidation peak current is linear with the concentration of formaldehyde in the range of 0.060 mM-20 mM with a detection limit of 0.022 mM. The latter exhibits a significant electrocatalytic activity toward N2H4. The oxidation peak current is linear with the concentration of f N2H4 in the range of 1μM-2.1 mM with a detection limit of 0.32μM. The HCHO sensor is shown to possess remarkable catalytic activity, good tolerance to CO poisoning and enhanced selectivity for the electrochemical oxidation of formaldehyde. The N2H4 sensor exhibits high sensitivity, good stability, fast response and low overpotential.2. Potentiostatic double-pulse method is used to prepare the Ag NPs/ZnO nannocomposites, and the electrochemistry and electrocatalysis of Ag NPs/ZnO are investigated. The PANI-SWCNTs composite film is synthesized in ionic liquid, and the electrochemistry and electrocatalysis of PANI-SWCNTs composite are investigated. Two nonenzymatic H2O2 sensors are proposed on the basis of the effective electrocatalytic activity of the Ag NPs/ZnO composite and PANI-SWCNTs composite towards reduction of H2O2. The former exhibits good linear behavior in the concentration range from 2μM to 5.5 mM for the quantitative analysis of H2O2 with a detection limit of 0.42μM. The latter exhibits good linear behavior in the concentration range from 5μM to 1 mM for the quantitative analysis of H2O2 with a detection limit of 1.2μM. The former is shown to possess superior properties of high sensitivity. The latter is shown to possess superior properties of good selectivity.3. HRP-SWCNTs-HA/GCE and HAp-GE-Hb/GCE chemically modified electrodes are fabricated, and the electrochemistry and electrocatalysis of HRP and Hb are investigated, and then new methods for H2O2 determination are established. The research shows that HRP and Hb molecules in the composite films retain their native structures and achieve their direct electrochemistry. The chemically modified electrodes show excellent electrocatalytic activity toward H2O2. The above studies indicate that novel nanocomposite can not only accelerate the direct electron transfer of redox proteins (enzymes) but also show excellent biocompatibility.4. A multifunctional electrochemical sensor based on AgHCF-PEDOT-GE ternary nanocomposite film modified electrodes is proposed. Electrochemical behavior of AA, DA, and UA is investigated at the modified electrode, and a differential pulse voltammetry method for simultaneous determination of AA, DA and UA is set up. The reults show that the chemically modified electrode shows excellent electrocatalytic activity toward AA, DA and UA. Shown by the results of differential pulse voltammetry, it has a good linearity of 1-2000μM,2-500μM and 0.8-500μM for AA, DA and UA, respectively. The sensor exhibits wide linear range and low overpotential.更多还原