【作者】 赵琨；

【导师】 何品刚； 方禹之；

【作者基本信息】 华东师范大学 ， 分析化学， 2007， 博士

【摘要】 纳米技术被公认为是21世纪最具有前途的科研领域。纳米材料从根本上改变了材料的结构,为克服材料科学研究领域中长期未能解决的问题开辟了新途径。纳米技术的研究和发展将会在信息技术、先进制造技术、医学和健康、环境、能源以及国家安全等方面产生突破。在众多的纳米材料中人们看好的是一种有中空管状结构的材料——碳纳米管。诺贝尔化学奖获得者Smalley曾经说过:“碳纳米管将是一种价格便宜、环境友好并且为人类创造奇迹的新材料。”自从1991年,纳米碳管(Carbon Nanotubes,CNTs)被日本电气公司(NEC)的饭岛澄男博士发现以来,以其所具有的很高的韧性、极强的导电性、优良的场发射性能、良好的金属性和半导体性等奇特的物理和化学性能被科学家称为未来的“超级纤维”。这一切吸引着全世界的科学家对其如痴如醉的研究。目前,利用纳米碳管的场发射特性制造的平面显示器件已经接近实用。利用纳米碳管的半导体特性研制新型电子器件的工作正全面展开。利用纳米碳管的机械性能织造的高强度纤维,已经装备了美国伞兵部队。利用碳纳米管来进行生物测定的应用正在取得快速进展。利用纳米碳管的吸附特性,制备储能物质,最终解决能源危机和环境污染问题,是各国政府都在下大本钱在做的事情。与其它分析方法相比,电化学传感器具有便携、成本低、灵敏度高、稳定性良好等优点。碳纳米管是制备修饰电极和电化学传感器的优良材料,因为碳纳米管是一种纳米材料,利用纳米材料对电极表面进行修饰时,除了可将材料本身的物化特性引入电极界面外,同时也会由于纳米材料的小粒径、大比表面积效应,使得粒子表面带有较多的功能基团而对某些物质的电化学行为产生特有的催化效应,表现为降低氧化过电势、增加峰电流、改善分析性能、提高方法选择性和灵敏度。目前对碳纳米管的合成、进一步的修饰改性以及对碳纳米管修饰电极的预处理、制作工艺的改进均有很大的空间。本文从分析的角度总结了碳纳米管的制备、纯化、修饰及其在电分析化学领域的研究情况。同时研究了多壁碳纳米管的修饰及其在DNA传感器上的应用,另一个工作重点在于低压下碳纳米管阵列的合成、修饰及其在葡萄糖传感器和亚硝酸盐传感器中的应用,目的在于促进碳纳米管在电分析化学领域的研究发展。论文共分三个部分,具体研究内容如下:第一部分绪论本章系统阐述了从碳纳米管的发现到目前电化学应用的研究进展。对于碳纳米管的发现、分类及结构、制备方法、生长机理、表征、分离与纯化、特性、化学改性、应用现状及研究前景等都有介绍。其中着重介绍了碳纳米管的物理和化学特性及化学修饰、碳纳米管阵列的制备、电化学应用。最后阐述本论文的目的和意义,指出论文的研究内容及创新之处。第二部分基于多壁碳纳米管修饰电极的电化学生物传感器研究纳米颗粒修饰的多壁碳纳米管在DNA电化学传感器中的研究。第一章基于二氧化锆纳米颗粒修饰的碳纳米管增强的DNA电化学传感器研究二氧化锆(ZrO2)是一种无机氧化物,具有热稳定性、化学惰性、无毒性等优点,另外它还能与含氧基团有较好的亲和作用,本文利用液相沉淀法将二氧化锆纳米颗粒修饰在碳纳米管表面,用DMF溶解混合均匀后滴涂到玻碳电极表面形成电极修饰物。通过二氧化锆与DNA末端磷酸基之间强烈的亲和作用将DNA固定到修饰电极表面。固定在ZrO2-CNTs上的DNA探针与溶液中的靶DNA杂交后,以电活性物质道诺霉素(DNR)为杂交指示剂。DNR的峰电流值与靶DNA浓度的对数值在2.25x10-9～2.25x10-12mol/L范围内呈良好的线性关系,DNA的最低检测下限为1.43×10-12mol/L。第二章耐而兰为嵌入剂金纳米颗粒修饰碳纳米管增强的DNA电化学传感器金(Au)纳米粒子对电化学杂交指示剂耐尔兰(NB)具有良好的催化作用,结合碳纳米管较大的比表面积和良好的电子传递性能及其羧基化后对探针DNA的共价固定作用,制备了灵敏度增强的电化学DNA生物传感器。首先合成了直径为16nm左右的Au纳米粒子,将其与末端羧基化的碳纳米管混合,所用溶剂为Nation。Nation是一种阴离子聚合物,它不仅可以作为溶剂,同时还能通过其与Au纳米粒子间的强烈作用形成网状物将Au纳米粒子固定在碳纳米管表面。通过DNA端部的-NH2与碳纳米管末端的-COOH之间的共价键和作用而将探针DNA固定到电极表面。与溶液中的靶DNA杂交后以NB为电化学杂交指示剂实现对互补序列、非互补序列的识别和电化学测定。第三部分碳纳米管阵列(ACNTs)的合成及其在电化学传感器中的应用碳纳米管阵列的低压合成及不同物质修饰的碳纳米管阵列增强的电化学传感器的研究。第一章低压下以酞菁铁为原料CVD法合成碳纳米管阵列的研究以金属有机化合物酞菁铁(FePc)为原料,利用其高温裂解可同时产生碳源和催化剂,通过调节真空反应室的气压,实现了在低压条件下气相沉积制备碳纳米管阵列,有效地降低了实验成本,提高了原料的利用率和碳纳米管的纯度,对碳纳米管的实际应用研究具有重要意义。利用扫描电子显微镜(SEM)和场发射扫描电子显微镜(FESEM),及透射电子显微镜(TEM)等分析手段,研究了碳纳米管在石英基底上的定向生长形态。通过对工艺参数的改进和优化,实现了定向碳纳米管阵列的批量制备,获得了大面积的、高度定向排列的碳纳米管阵列。同时详细讨论了工艺参数对高温裂解法制备的定向碳纳米管生长的影响,并对碳纳米管的场发射性能及超电容特性进行了研究。第二章基于钯纳米颗粒修饰的碳纳米管阵列的葡萄糖电化学传感器研究钯(Pd)在化学反应中主要作催化剂,比较稳定,能耐酸的侵蚀。钯的化合物易加热分解或还原成金属钯,同时钯有形成配位化合物的强烈倾向。本文就是利用纳米钯颗粒易形成配位化合物、比表面积大、表面反应活性高、表面活性中心多、催化效率高、吸附能力强等这些优异性质,把钯颗粒引入到葡萄糖传感器研究中。0.4V(Vs.SCE)工作电位下测定该传感器对葡萄糖的电流响应,在3×10-5～6×10-4 mol/L范围内葡萄糖浓度与电流呈现良好的线性关系。以3倍空白值的标准偏差计算此传感器的检测限为7.26×10-6 mol/L。第三章基于铂纳米颗粒修饰的碳纳米管阵列的葡萄糖电化学传感器研究本实验以碳纳米管阵列为导电基质,采用化学还原法在碳纳米管表面直接制备了铂(Pt)纳米颗粒,从而得到铂纳米颗粒修饰的碳纳米管阵列电极(Pt-ACNTs),研究了此电极的电化学性质并制成葡萄糖生物传感器进行葡萄糖的检测。由于铂纳米粒子极好的催化能力以及碳纳米管阵列较大的比表面积和良好的电子传递性能,此传感器具有响应时间短、灵敏度高、抗干扰能力强等特点。实验结果表明,0.3V(vs.SCE)工作电位下测定该传感器对葡萄糖的电流响应,在1×10-5～7×10-3 mol/L范围内葡萄糖浓度与电流呈现良好的线性关系。以3倍空白值的标准偏差计算此传感器的检测限为8.89×10-6mol/L。第四章基于硫堇修饰的碳纳米管阵列的亚硝酸盐电化学传感器研究硫堇(Thionine)是一种紫色染料,其分子为含两个氨基的平面结构,易溶于水。通过与碳纳米管之间很强的π一π非共价键合作用相结合,能够给碳纳米管表面带来丰富的氨基。本实验采用将硫堇修饰的碳纳米管阵列制备成电极,利用碳纳米管的催化特性与硫堇分子质子化后对亚硝酸根的富集原理,检测亚硝酸根的氧化峰。结果表明亚硝酸根在硫堇修饰碳纳米管阵列电极上于0.78V(vs.SCE)出现一个灵敏的氧化峰,示差脉冲伏安法(DPV)测定其氧化峰电流与亚硝酸根浓度在3×10-6～5×10-4mol/L范围内呈现良好的线性关系,最低检出限(3s)为1.12×10-6mol/L,对1×10-5 mol/L亚硝酸根进行11次平行测定,其相对标准偏差为2.75%,该修饰电极制作简单,重现性良好,将本法用于香肠样品中亚硝酸根的测定,结果令人满意。更多还原

【Abstract】 Nanotechnology is recognized as the most promising scientific research domain in the 21st century. The nanomaterials fundamentally changed the material structure and provided the new approachs which was not resolved in the materials science research area for the past few years. The nanotechnology research and development will produce new breakthrough in the aspects of information technology, advanced technique of manufacture, medicine and health, environment, energy as well as national security, and so on. A favorable material in the multitudinous nanomaterials is a kind of hollow tubal-shape structure material—Carbon Nanotubes. The Nobel chemistry prize winner Smalley has said that the carbon nanotubes will be a kind of low-cost, environment friendly new material, which can create the miracle for humanity.Since discovered by doctor S.Iijima of Japanese Electron Company’s in 1991, carbon nanotubes was called the future super fiber by scientists for their unusual physical and chemical performance, such as the high toughness, great electro-conductivity, fine field emission performance, good metallicity and the semi-conductive property. All of these are attracting the scientists devote into the research of carbon nanotubes deeply. At present, plane display approached practicality using the field emission characteristic of carbon nanotubes. The work of manufacturing new electronic device is developing roundly that used the semiconducting characteristic of carbon nanotubes. The high strength fiber produced using the mechanical property of carbon nanotubes has already equipped US Parachute troops. Each government is exerting their utmost to solve the energy crisis and the environmental pollution problem by the preparation of the energy storage material using the adsorptive characteristic of carbon nanotubes. The application on biological detection has been progress badly based on carbon nanotubes. Comparing with other analysis methods, the electrochemical sensor has many merits, for instance, the portability, low cost, high sensitivity, best stability and so on. Carbon nanotubes are fine material on modified electrode and electrochemical sensor because it is nanomaterial and it could introduce its excellent charictristic on the surface of electrode, such as small diameter and big ratio surface area effect. The function groups on the surface of carbon nanotubes could catalyze the electrochemical behavior of some substance and exhibit in reducing oxidate potential, increasing peak current, improving analysis performance and enhancing the selectivity and sensitivity of the method.There is big room for the synthesis, modified and pretreatment of the carbon nanotubes at present. This article summarized the domain research situation of the preparation, purification, modifiability of carbon nanotubes and studied the modified and applications of the carbon nanotubes on DNA biosensor simultaneously. Another important work lies in the synthesis of aligned carbon nanotubes under the low pressure and applications of aligned carbon nanotubes in the glucose biosensor and the nitrite sensor. The aim of all the above investigation is to promoting the development of the carbon nanotubes in electroanalitical chemical domain. This paper altogether divided into three parts. The details are given as follows:Part One: PrefaceIn this chapter, we elaborated review from the discovery to the applications of carbon nanotubes on electrochemistry to the present. The discovery, the classification and the structure, the preparation method, the growth mechanism, the test, separation and purify, the characteristic, chemistry modification and application, present situation and the research prospect all have been introducded. In which emphatically introduced the physical and the chemical characteristics, the chemical modification, the preparation and the electrochemical application of carbon nanotubes. Finally, expounded the aim and the significance, pointed out the research content and the innovation in this paper. Part Two: Electrochemical Biosensor Based on Multiwalled Carbon NanotubesChapter One: Electrochemical Detection of DNA Hybridization Using Zirconia Nanoparticles Supported on Carbon NanotubesZirconia （ZrO₂） is a kind of inorganic oxide and it has merits of thermal stability, chemistry inertia and nontoxicity, moreover it also has good affinity with the oxygenous groups. In this article we deposited the zirconia nanoparticles onto the surface of carbon nanotubes by using the liquid phase deposition method. Then dissolved it in DMF and drop the compound onto the surface of carbon nanotubes and the modified electrode was obtained. There is strong affinity between Zirconia and PO₄-DNA through which the PO₄-DNA could be immobilized on the surface of electrode.After hybridized with ds-DNA, the peak current of DNR was increased. The cathodic peak current of daunomycin after hybridization with the target DNA was linearly related to the logarithmic value of the target DNA concentration ranging from 2.25×10^-9 to 2.25×10^-12mol/L. A detection limit of 1.43×l0¹²mol/L of oligo-nucleotides can be estimated.Chapter Two: Electrochemical Detection of DNA Bybridization Using Nile Blue and Au Nanoparticles Supported on Carbon Nanotubes Modified ElectrodeDue to the good catalytic activity of gold （Au） nanoparticles to the electrochemistry hybridizing indicator Nile Blue （NB） and the good charge transport characteristic of carbon nanotubes, a novel and sensitive electrochemical DNA biosensor is described. First, synthesized the Au nanoparticles with the diameter of 16nm and mixed it with the carboxylic carbon nanotubes in Nafion solution. Oligonucleotide probes with amido group at the 5’ end were attached onto the carboxyl supported on carbon nanotubes. Nile blue （NB） is the hybridizing indicator and the experimental parameter of NB was detected. The complementary DNA detection sensitivity was dramatically increased.Part Three: Electrochemical Sensor Based on Aligned Carbon Nanotubes Chapter One: Synthesis of Aligned Carbon Nanotubes with Low Pressure by CVD of FePcOrgano-metal phthalocyanine iron （FePc） is the raw material because it would pyrolysis and simultaneously produce the catalyst in the process of CVD synthesis of aligned carbon nanotubes. Through the adjustment of the pressure of the vacuum reaction chamber, the pure aligned carbon nanotubes were obtained and it also reduced the experimental cost effectively which provide significance to the practical application research of aligned carbon nanotubes. SEM, FESEM and TEM was used as the analysis methods on the appearance of aligned carbon nanotubes which was growned on quartz basis. Batch production of big area, exact directional aligned carbon nanotubes has been obtained through improved and optimized the craft parameter. Simultaneously we also discussed in detail the the influence of craft parameter to the aligned carbon nanotubes. The field launch performance and the ultra electric capacity characteristic are studied in the article.Chapter Two: Glucose Biosensor Based on Pd Nanopartides and Glucose Oxidase on Aligned Carbon Nanotubes ElectrodePd is the catalyst in some chemical reaction for its stable, acidproof character. The Pd compound could be easily pyrolyzed and be deoxidizec to Pd（0）, simultaneously Pd presents the tendency to form the coordination compounds intensely. In this article we introduced the outstanding nature of Pd nanopartides such as the easy formation of the coordination compound, the big surface area, the high surface reaction activeness, the much activity center of its surface, the high catalyzed efficiency, the strong adsorptive capacity into the glucose biosensor research. The enzyme electrode exhibits excellent response performance to glucose with linear range from 3×10^-5-6×10^-4mol/L at the working potential of 0.4V. A detection limit of 7.26×10^-6 is observed with this biosensor when signal to noise is 3.Chapter Three: Glucose Biosensor Based on Pt Nanoparticles and Glucose Oxidase on Aligned Carbon Nanotubes Electrode A sensitive amperometric glucose biosensor based on platinum nanoparticles （PtNPs） combined aligned carbon nanotubes （ACNTs） electrode was investigated. PtNPs which can enhance the electrocatalytic activity of the electrode for electro-oxidating hydrogen peroxide by enzymatic reaction, were electrocrystallized on 4-aminobenzene monolayer-grafted ACNTs electrode by potential-step method. These PtNPs combined ACNTs’ （PtNPs/ACNTs） surfaces were characterized by scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. The highly dispersed PtNPs on ACNTs can be obtained. The enzyme electrode exhibits excellent response performance to glucose with linear range from 1×10^-5～7×10^-3 M and fast response time within 5s. Furthermore, this glucose biosensor also has good reproducibility. It is demonstrated that the PtNPs/ACNTs electrode with high electrocatalitic activity is a suitable basic electrode for preparing enzyme electrodes.Chapter Four: Determination of Nitrite with the Electrocatalytic Property to the Oxidation of Nitrite on Thionine Modified Aligned Carbon NanotubesA thionine modified aligned carbon nanotubes （ACNTs） electrode was fabricated and was used to electrochemically determine nitrite. The thionine modified ACNTs electrode exhibited enhanced electrocatalytic behavior to the oxidation of nitrite. The electrochemical mechanism of the thionine/ACNTs electrode towards the oxidation of nitrite was discussed. The thionine modified ACNTs electrode exhibited fast response towards nitrite with a detection limit of 1.12×10^-6 mol L^-1 and a linear range of 3×10^-6～ 5×10^-4 mol L^-1. The proposed method was successfully applied in the detection of nitrite in real samples.更多还原