几种功能化石墨烯纳米复合材料的制备及其电化学传感研究

发布时间：2018-01-29 17:06

本文关键词： 功能化石墨烯电化学传感平台二茂铁衍生物聚多巴胺-还原氧化石墨烯重金属离子　出处：《湖南师范大学》2016年硕士论文　论文类型：学位论文

【摘要】：电化学传感器具有灵敏度高、操作简便、检测速度快、不需要复杂前处理、成本低等优点,因此在分析化学领域被广泛应用。纳米材料因其优良和独特的性能而被研究者大量研究,并在工业、材料、生物、物理、化学等学科和领域都发挥着重要作用。将纳米材料应用在电化学生物传感中,能够很好地提高响应速率,拓宽线性范围,降低检测限,增强稳定性等。石墨烯因其特殊的二维层状结构和优异的光学、电学、热学、力学性能而受到科研工作者的关注。基于此,本论文以石墨烯为主体,设计并且合成了几种功能化石墨烯纳米复合材料,利用各种手段对功能化石墨烯纳米复合材料的形貌、结构、导电性等进行了表征,并研究了这些复合材料修饰电极在电化学传感方面的应用。主要工作内容如下：1.将一种新型的二茂铁衍生物(Fc-NH_2)共价键合到氧化石墨烯(GO)表面,制备了新型二茂铁衍生物功能化的氧化石墨烯(GO-Fc-NH_2)。通过电化学法,将此复合物与氯金酸(HAuCl_4)共还原电沉积到玻碳电极表面(GCE)制备了rGO-Fc-NH_2/AuNPs/GCE。rGO-Fc-NH_2/AuNPs内米复合膜不但拥有良好的导电性和生物相容性,而且可以有效地防止电子媒介体二茂铁衍生物从电极表面泄漏到溶液中。该材料同时拥有纳米材料和电子媒介体的优点。利用纳米材料和电子媒介体的协同催化效应、纳米复合材料大的比表面积以及对双酚A (BPA)勺吸附和富集作用,成功构建了一个用于超灵敏检测BPA的电化学传感平台。因此,将电子媒介体修饰在纳米材料上能够极大增强传感器的电化学性能,这也可为制备更多新型电活性纳米材料及电化学传感器提供新思路。2.基于新型有机荧光探针2-羟基菲并咪唑衍生物(Pi-A)功能化石墨烯,制备了Pi-A/RGO复合物修饰电极,作为一种新型的电化学传感器用于高灵敏检测铜(Ⅱ)离子。Pi-A通过π-π共轭与石墨烯作用,固定在石墨烯的表面,得到Pi-A/RGO复合物。该复合物能够选择性地高效捕捉铜(Ⅱ)离子。在优化的实验条件下,此修饰电极能够成功用于自来水、湖水、河水、山泉水等实际水样中铜(Ⅱ)离子的检测,且其他多种重金属离子对铜(Ⅱ)离子的检测没有影响。因此,这种将有机探针分子与石墨烯结合的方法能够进一步扩展荧光探针在生物和电化学传感领域的应用。3.受贻贝粘附蛋白启发,采用多巴胺作为还原剂来还原氧化石墨烯,同时基于多巴胺能在弱碱性条件下发生自氧化聚合形成聚合物膜的特性,制备出聚多巴胺修饰还原型氧化石墨烯(PDA-RGO)复合物,再利用PDA-RGO表面的儿茶酚结构在弱碱性条件下能与带有氨基、巯基等基团的分子进行迈克尔加成或席夫碱反应,使其进一步功能化接合不同分子从而得到多功能电化学平台。选用4-(二茂铁基-2-乙炔基)苯胺(Fc-NH_2)、半胱氨酸(cys)、葡萄糖氧化酶(GO_x)等典型含硫醇或氨基的化合物作为模型分子锚定在PDA-rGO表面上得到不同的电化学检测平台。嫁接有二茂铁衍生物的复合物对许多电活性分子具有很好的催化活性,可用于单独或同时检测多巴胺(DA)和尿酸(UA)、对苯二酚(HQ)和邻苯二酚(CC)。而嫁接了半胱氨酸后的PDA-rGO复合物修饰电极,可以同时检测pb~(2+0和Cd~(2+0。此外,将GO_x-PDA-rGO修饰在玻碳电极上,可以明显观察到GO_x的直接电子转移的特征吸收峰,且当加入葡萄糖时,GO_x-PDA-rGO/GCE修饰电极对葡萄糖具有良好的电流响应。因此,该多功能电化学检测平台可以通过改变表面修饰的官能团来有效调节电极表面的结构和性质,操作简单、方便。本研究利用化学反应构建电化学检测平台,也为设计更多的电化学检测或传感平台提供了一种更加灵活有效的方法。
[Abstract]:The electrochemical sensor has high sensitivity, simple operation, fast detection speed, without complicated pretreatment, low cost, so it is widely used in the field of analytical chemistry. Nano materials because of their excellent and unique properties can be a large number of researchers and research in industrial, material, biology, physics, chemistry and other disciplines and fields it has played an important role. The nano materials used in electrochemical biosensors, can greatly improve the response rate, broaden the linear range and lower detection limit, enhance the stability of graphene. Because of its special two-dimensional layered structure and excellent optical, electrical, thermal, mechanical properties and based on the attention of scientists. This, in this paper, graphene as the main body, and the design of several functionalized graphene nanocomposites were synthesized by various means, the structure morphology of the functionalized graphene nano composite material, conductive Were characterized, and the applications of these composite materials modified electrodes in electrochemical sensor. The main contents are as follows: 1. a new type of two ferrocene derivatives (Fc-NH_2) covalently bonded to the graphene oxide (GO) surface, for preparing two new ferrocene derivative graphene oxide function the (GO-Fc-NH_2) by electrochemical method, the complex with chloroauric acid (HAuCl_4) coreduction electrodeposited onto the surface of glassy carbon electrode (GCE) was prepared in the rGO-Fc-NH_2/AuNPs/GCE.rGO-Fc-NH_2/AuNPs composite film not only has good conductivity and biocompatibility, and can effectively prevent the electron mediator two ferrocene derivatives from the electrode surface leakage into the solution. The material also has the advantages of nano materials and electronic media. The synergistic catalytic effect of nano materials and electronic media, nano composite materials with high surface area And on bisphenol A (BPA) adsorption and enrichment, successfully constructed one for electrochemical sensing platform for ultrasensitive detection of BPA. Therefore, the electronic media modification can greatly enhance the electrochemical performance of the sensor in nanometer materials, it can also provide new ideas for the new.2. organic fluorescent probe 2- hydroxy phenanthroimidazole derivatives based on the preparation of more new electroactive nano materials and electrochemical sensors (Pi-A) functionalized graphene, Pi-A/RGO composite modified electrode was prepared as a novel electrochemical sensor for high sensitive detection of copper (II) ions.Pi-A by tt-tt conjugate and graphene, fixed on the surface of graphene Pi-A/RGO, are complex. The complex can selectively and efficiently capture copper (II) ions. Under the optimized experimental conditions, the modified electrode can be successfully used in tap water, lake water, river water, spring water etc. In water samples of copper (II) ion detection, and other kinds of heavy metal ions on copper (II) ions did not affect detection. Therefore, this method of organic probe molecules and graphene can be further combined with the extended application of.3. fluorescent probes in biological and electrochemical sensing fields inspired by mussel adhesion protein, using dopamine as a reducing agent to reduction of graphene oxide, and dopamine self oxidation polymerization characteristics of polymer film formation in alkaline conditions based on the preparation of poly dopamine modified Shi Moxi type reduction oxidation (PDA-RGO) complexes, using catechol structure on the surface of PDA-RGO with amino in alkalescent condition, Michael addition or mat Schiff reaction molecules of sulfydryl groups, which further functionalized with different molecular bonding to obtain multifunctional electrochemical platform. Using 4- (Er Maotie -2- ethynyl) benzene Amine (Fc-NH_2), cysteine (Cys), glucose oxidase (GO_x) and other thiol containing amino compounds or typical as model molecules anchored by electrochemical detection of different platforms on the PDA-rGO surface. Grafting complex with two ferrocene derivatives have good catalytic activity for many electroactive molecules, can be used alone or in simultaneous determination of dopamine (DA) and uric acid (UA), hydroquinone (HQ) and catechol (CC). The grafting modification of PDA-rGO composite electrode of cysteine, which can simultaneously detect pb~ (2+0 and Cd~ (2+0. in addition, GO_x-PDA-rGO was modified on the glassy carbon electrode, it can be observed that the characteristics of direct electron GO_x the transfer of the absorption peak, and in the presence of glucose, GO_x-PDA-rGO/GCE modified electrode has good current response. Therefore, the multifunctional electrochemical detection platform can change the surface modified by functional group effectively on glucose Adjusting the structure and properties of electrode surface is simple and convenient. In this study, the electrochemical detection platform was constructed by chemical reaction, and it provides a more flexible and effective way for designing more electrochemical detection or sensing platform.

【学位授予单位】：湖南师范大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O657.1;TP212

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