功能化石墨烯复合材料的电化学行为研究及其在活体中信息分子的实时检测

发布时间：2018-05-19 20:23

本文选题：石墨烯 + 功能化　；参考：《华东师范大学》2015年博士论文

【摘要】：石墨烯是单层碳原子厚度的碳材料,是继碳纳米管之后科学界发现的最重要的碳材料。石墨烯具备卓越的电学和光学性能,且机械和热学优良性能突出,迅速成为21世纪最重要的纳米材料之一。它的出现及快速发展,为药物释放、纳电子器件、超级电容器和储氢等领域提供了巨大的机遇。同时,石墨烯超快速的电子迁移率、超大的比表面积、优良的材料兼容性,为石墨烯在电化学传感方面的广泛应用创造了广阔的空间。遗憾的是,纯石墨烯之间存在非常强劲的范德华力,容易发生团聚堆积,形成堆积石墨烯。堆积石墨烯的各方面性能大大下降,阻碍了石墨烯前进发展的道路。不过,石墨烯兼容性良好,因此,科学家们在石墨烯表面嫁接各种功能化单体,设计了多种多样的功能化石墨烯。例如,在石墨烯表面修饰亲水性的功能基团,可以防止石墨烯之间的团聚,改善石墨烯的水分散性。在石墨烯表面修饰各种纳米材料,可以发挥各材料之间的性能协同性,为其在其它领域的应用打开一扇新的大门。在石墨烯表面修饰识别单元,可以联系材料与分析学科之间的优势,拓展交叉学科之间的有机结合。为了设计高效的电化学分析平台,我们将功能化石墨烯的卓越电学性能与特定的识别单元合理组装,以实现多种生物信息分子的灵敏监测。目前,采用电化学分析平台分析生物信息分子主要采用的是传统的离线平台。即将生物处死取脑切片培养或者匀浆后,收集样品,在平台上分析检测。通过这样分析的样品是单一的、静止的、片面的,难以实现生物信息分子从源头上的直接检测。微渗析活体取样技术历史悠久,可以在不干扰动物正常生命活动的前提下,实现信息分子样品的实时、在线、连续采集。然而,样品体积小,易变质等缺点限制了它的普遍使用。本文中,我们通过设计高效的功能化石墨烯电化学平台,与微渗析活体取样技术联角,可以实现生物信息分子实时、在线、连续的分析,监测生物信息分子源头上的直接变化。本论文分为五个部分,具体内容如下：第一章绪论本章主要介绍了石墨烯的兴起、功能化及其功能化石墨烯在电化学传感中的广泛应用,微渗析活体取样技术的概括及其与电化学分析平台的联用,着重介绍了石墨烯的功能化及其功能化石墨烯构建的电化学分析平台应用。第二章石墨烯/g-C3N4层状复合材料的制备及其电催化行为的研究本工作中,我们将g-C3N4的催化特性和石墨烯的高导电性能有机的结合,设计了石墨烯/g-C3N4 (G-g-C3N4)新型复合材料。同时,G-g-C3N4复合材料在氧化还原体系中的电化学行为显示G-g-C3N4的电子传递速率较石墨烯均有明显地改善。通过G-g-C3N4复合材料分别对还原型生物分子(尿酸、去甲肾上腺素、酪氨酸、色氨酸、对乙酰氨基酚和芦丁)和氧化型生物分子(H202和02)的电催化活性研究,我们发现了适量的g-C3N4负载于石墨烯的表面能有效的改善材料的电子转移速率,最大限度的发挥材料之间的协同效应。这归根于复合材料独特的电子层结构,石墨烯与g-C3N4之间能很好地发挥协同作用,而且,在材料构筑过程中,G-g-C3N4对石墨烯的高温还原具备一定的模板效应。第三章贵金属掺杂石墨烯／氧化锌复合材料的制备及其电催化行为的研究本文利用石墨烯具备传递和储存电子的能力,通过光化学还原法合成了几种不同的贵金属(Ag, Pd, Au, Pt)负载于石墨烯表面。本文利用紫外光激发ZnO中的电子和空穴对发生分离,自由电子储存于石墨烯中。贵金属离子加入后,捕捉自由电子发生还原反应,形成相应的贵金属颗粒。根据贵金属的尺寸和分布,我们将它们分为两类：PdPt和AgAu。同时,我们考查了这几种复合材料对H202的电催化活性,发现Pd和Pt复合材料由于颗粒较小,分布较均匀,表现出更为突出的电催化行为。第四章GS/ZnO/Pd双通道电化学系统的研究及其对自由移动大鼠脑内葡萄糖与乳酸水平的同时测定本工作中,我们从前面研究的基础上,挑选了电化学活性最优的Pd复合材料(GS/ZnO@Pd).利用该复合材料优良的电催化性能,结合两种识别单元(葡萄糖氧化酶和乳酸氧化酶)构筑了双通道电化学传感器。我们通过该双通道传感器与微渗析活体取样联用,构建了葡萄糖和乳酸同时在线检测的平台。结果表明,该分析平台对葡萄糖和L-乳酸可以实现高灵敏、高选择性的检测。因此,我们将它应用于监测自由移动大鼠脑内纹状体区的葡萄糖和L-乳酸水平,结果表明,葡萄糖和乳酸水平分别为0.323±0.021 mM and 0.501 mM±0.057 mM(mean± s.d.,n=3)。第五章功能化石墨烯修饰电化学传感的构筑及其对大鼠纹状体中葡萄糖在线检测的研究本工作中,我们首先用共价健合的方法分别制备了氨基离子液体功能化的石墨烯(IL-RGO)与磺酸基功能化(S-RGO)的石墨烯,分别使石墨烯的表面带上正负电荷。我们通过层层组装技术实现了功能化石墨烯的自组装,达到了复合材料{IL-RGO/S-RGO}n的可控合成。采用H202为探针,我们进一步优化了复合材料的层数,自组装葡萄糖氧化酶后,构筑了葡萄糖电化学传感器。与微渗析活体取样技术联用,我们构建了葡萄糖实时、在线、连续检测的可靠平台。该平台实现了对大鼠正常状态下及其腹腔注射30μL胰岛素刺激状态下的葡萄糖水平的实时、在线、连续的监测。结果表明,正常状态下葡萄糖水平为0.376±0.028 mM(mean±s.d.,n=3),胰岛素刺激下,葡萄糖水平(30 min)有所下降,下降幅度为52.75±8.6%(mean±s.d.,n=3)。
[Abstract]:Graphene is a carbon material with the thickness of a single carbon atom. It is the most important carbon material found by the scientific community following the carbon nanotubes. Graphene has excellent electrical and optical properties, and has excellent mechanical and thermal properties. It has rapidly become one of the most important nanomaterials in the twenty-first Century. Its emergence and rapid development, drug release, and nanowires The devices, supercapacitors and hydrogen storage provide great opportunities. At the same time, the ultra fast electron mobility, large specific surface area and excellent compatibility of graphene have created wide space for the extensive application of graphene in electrochemical sensing. Unfortunately, there is a very strong Fan Dehua force between pure graphene, It is easy to accumulate accumulation and form accumulated graphene. The properties of the accumulated graphene are greatly reduced and the way to advance the development of graphene is hindered. However, the compatibility of graphene is good, so scientists have grafted various functional monomers on the surface of graphene and designed various functional fossils. For example, on the surface of graphene. The modification of hydrophilic functional groups can prevent the aggregation of graphene and improve the water dispersibility of graphene. The modification of various nanomaterials on the surface of graphene can give play to the performance synergy between various materials and open a new gate for its application in other fields. The surface modification identification unit of graphene can contact the material. In order to design a highly efficient electrochemical analysis platform, we assemble the excellent electrical properties of functional fossils with specific identification units to realize the sensitive monitoring of a variety of biological information molecules. At present, the electrochemical analysis platform is used to analyze the bioinformatics. It is the traditional off-line platform that is used as a traditional off-line platform. After the biological execution of the brain slices for culture or homogenate, samples are collected and analyzed on the platform. The sample is single, static and one-sided, and it is difficult to realize direct detection of biological information molecules from the source. Microdialysis sampling technique has a long history. We can realize real-time, online, continuous collection of information molecular samples without interfering with normal life activities of animals. However, the shortcomings of small volume and metamorphism limit its universal use. In this paper, we can implement the electrochemical platform of efficient functional fossil ink and can be combined with microdialysis sampling technique. Biological information molecules are in real time, online and continuous analysis to monitor the direct changes on the source of biological information molecules. This paper is divided into five parts. The first chapter is the introduction of the introduction of the rise of graphene, functionalization and the extensive application of functionalized fossils in electrochemistry sensing, microdialysis sampling technique In conjunction with the electrochemical analysis platform, the functionalization of graphene and the application of the electrochemical analysis platform for the construction of functional fossils are emphatically introduced. In the second chapter, the preparation and electrocatalytic behavior of graphene /g-C3N4 layered composite materials and its electrocatalytic behavior are studied. In this work, the catalytic properties of g-C3N4 and the high conductivity of graphene are introduced. A new type of graphene /g-C3N4 (G-g-C3N4) composite has been designed organically. At the same time, the electrochemical behavior of G-g-C3N4 composites in the redox system shows that the electron transfer rate of G-g-C3N4 is obviously improved than that of graphene. By G-g-C3N4 composites, the reductive biomolecules (uric acid, norepinephrine, cheese) The electrocatalytic activity of ammonia, tryptophan, paracetamol and rutin and oxidized biomolecules (H202 and 02) has been studied. We found that a proper amount of g-C3N4 loaded on the surface of graphene can effectively improve the electron transfer rate of the material and maximize the synergistic effect between the materials. This is attributed to the unique electronic layer of the composite. Structure, the synergism between graphene and g-C3N4 can be played well, and in the process of material construction, G-g-C3N4 has a certain template effect on the high temperature reduction of graphene. Third the preparation and electrocatalytic behavior of the noble metal doped graphene / Zinc Oxide composite and its electrocatalytic behavior Several different precious metals (Ag, Pd, Au, Pt) are loaded on the surface of graphene by the photochemical reduction method. The electron and hole pairs in ZnO are separated by ultraviolet light and free electrons are stored in graphene. After the addition of precious metal ions, the free electrons are captured and the corresponding precious metals are formed. Particles. According to the size and distribution of precious metals, we divide them into two types: PdPt and AgAu., we examine the electrocatalytic activity of these composite materials to H202. It is found that Pd and Pt composites have more prominent electrocatalytic behavior because of smaller particles and more uniform distribution. The fourth chapter GS/ZnO/Pd dual channel electrochemical system In the study and the simultaneous determination of glucose and lactic acid in the brain of free moving rats, we selected the Pd composite (GS/ZnO@Pd) with the best electrochemical activity on the basis of the previous study. Using the excellent electrocatalytic properties of the composite, two kinds of identification units (glucose oxidase and lactate oxidase) were constructed. The dual channel electrochemical sensor is used to construct a platform for simultaneous determination of glucose and lactic acid by the dual channel sensor combined with microdialysis sampling. The results show that the platform can be highly sensitive and highly selective for glucose and L- lactic acid. The glucose and L- lactate levels in the intracerebral striatum showed that glucose and lactic acid levels were 0.323 + 0.021 mM and 0.501 mM + 0.057 mM (mean S.D., n=3). Fifth chapters of functional fossils modified electrochemistry sensing construction and the study of glucose line detection in the striatum of rats, we first used covalent The functionalized graphene (IL-RGO) and the sulfonic functionalized (S-RGO) graphene were prepared by the combined method, and the surface of the graphene was positive and negative, respectively. We realized the self assembly of the functional fossils by layers assembly technology, and achieved the controllable synthesis of the composite {IL-RGO/S-RGO}n. H202 The probe, we further optimized the number of composite materials, constructed the glucose electrochemical sensor after self assembly of glucose oxidase. Combined with microdialysis sampling technique, we constructed a reliable platform for real-time, on-line and continuous glucose detection of glucose. The platform has achieved 30 micron L insulin injection in the normal state of rats and the intraperitoneal injection of glucose. The glucose level in the stimulated state was monitored on line and on line. The results showed that the glucose level was 0.376 + 0.028 mM (mean S.D., n=3) under normal condition. The glucose level (30 min) decreased with the insulin stimulation, and the decrease was 52.75 + 8.6% (mean S.D., n=3).
【学位授予单位】：华东师范大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TB33;O613.71

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