纳米材料化学传感器的研究与应用

【作者】 张幸儿；

【导师】 胡效亚；

【作者基本信息】 扬州大学 ， 分析化学， 2005， 硕士

【摘要】 纳米材料由于具有高的比表面积和一些特殊的结构,从而成为一类具有特殊效应的传感材料。目前,这方面的研究已经成为热点,纳米材料在传感器应用中的重要特点就是基于纳米材料的高比表面积所导致的对传感信号的放大功能。本文利用本课题组与他人合成的一些纳米材料制成修饰碳糊电极,初步开展这方面的一些研究工作。 一、铜纳米粒子修饰碳糊电极测定氨基酸 本文利用铜纳米粒子（平均粒径d≈50nm）修饰的碳糊电极,实现了电化学方法在近中性（pH=8磷酸缓冲溶液）条件下,对甘氨酸等15种氨基酸的定量测定。在无水乙醇体系中,水合肼还原硫酸铜制备铜纳米粒子,以之制成修饰碳糊电极,利用循环伏安法测定氨基酸,测定的线性范围为（甘氨酸）:2.5×10^-5 mol/L～7.4×10^-4mol/L,最低检测下限（甘氨酸）:2.5×10^-6 mol/L（S/σ>3）。 二、直接电位法测定水中H₂O₂ 本文提供了一种不需活化,具有良好线性范围和灵敏度的过氧化氢选择性电极。用甲基苯基硅油、二氧化锰和碳粉制作碳糊电极,在0.05 mol/LH₃PO₄溶液中（20℃）用直接电位法测定过氧化氢,具有四个数量级的线性范围(1.08×10^-5mol/L～0.104 mol/L),灵敏度:63.02 mV/pH₂O₂,检测下限:6.22×10^-7mol/L,电极具有良好的选择性,大多数常见阴阳离子不会对测定有明显干扰作用。该电极在pH=7.4时,也可准确测定H₂O₂,响应斜率为31.0 mV/pH₂O₂。 三、无基准物电位滴定过氧化氢 本文设计的β-MnO₂纳米棒修饰的碳糊电极可以作为指示电极,对过氧化氢第一次实现无基准物电位滴定。β-MnO₂纳米棒可以由水热法很方便的制得。在更多还原

【Abstract】 Nano-materials has great surface area and some special structures, so that it has become a kind of sensor’s materials possessing special properties, Nowdays, the study about which has become the focus. It is main character in nano-materials’ application of sensors that the amplificatory effect to the signal of the sensor attributing to great surface area of nano-materials. With the nano-materials prepared by our group and others, this paper makes some researchs about chemical sensors that the carbon paste electrodes modified by nano-materials.1 Electrochemical determination of amino acid with carbon paste electrode modified by copper nanoparticlesWith carbon paste electrode modified by copper nanoparticles （average diameter of nanoparticles d≈50nm）, direct electrochemical detection of fifteen kind amino acids （including glycine） is firstly achieved in approximately neutral solution（pH=8.0 phosphate buffer solution）. The copper nanoparticles can be obtained by reducing CuSO₄ with N₂H₄·H₂O in the ethanol. Then, the carbon paste electrode modified by copper nanoparticles can be used to determine amino acids with Cyclic Voltammetry. About the determination, the linear range of detection（glycine） is 2.5 X10^-5 mol/L⁷.4X 10^-4 mol/L, and the detection of limit （glycine） is 2.5 X 10^-6 mol/L （S/σ>3 ） .2 Direct potentiometric determination of H₂O₂ in waterThere is hydrogen peroxide sensor that don’t need to be activated , and which has nice linear range with high sensitivity. The chemical modified carbon paste electrode（CMCPE） is made up of carbon power, manganese dioxide and silicone oil II. In the 0.05 mol/L phosphate solution（20℃）, the CMCPE gives that five magnitudes’ linear range 1.08X 10^-5 mol/L -0.104 mol/L, with a sensitivity of 63.02 mV/pH₂O₂ and a detection limit of 6.22 X 10^-7mol/L by the direct potentiometry, the CMCPE has fine selectivity, i.e. most anion and cation don’t interfere with the detection. Moreover, theCMCPE can be used in pH=7.4 phosphate buffer solution, and has a sensitivity of 31.0 mV/pH₂O₂.3 No standard reagent potentiometric titration of hydrogen peroxideThe carbon paste electrode modified by β-MnO₂ nanorods （CMCPE） is used as the indicator electrode, no standard reagent potentiometric titration of hydrogen peroxide is the first realized. β-MnO₂ nanorods can be prepared very easily with hydrothermal method. With the hydrogen peroxide solution adding and reaching a certain concentration, the potential of the CMCPE would provide a enormous change in pH=3.0 phosphate buffer solution. The end-point of potentiometric titration has relation to the concentration of hydrogen peroxide, According to which, quantitative analysis of the hydrogen peroxide can be achieved. The method is no standard reagent, simple, precise and can be used as a convenient determination of hydrogen peroxide.更多还原