信号放大的电化学DNA传感器的制备及应用

发布时间：2018-06-15 00:11

本文选题：电化学DNA传感器 + 信号放大　；参考：《安徽师范大学》2017年硕士论文

【摘要】：近年来,电化学生物传感器以其诸多优点,如仪器简单、成本低廉、响应迅速、灵敏度高,而被广泛应用于生物分析领域。同时,由于DNA的多样结构、可组装、可折叠、可识别等性质,电化学DNA传感器不仅广泛应用于DNA损伤、杂交的检测,还可实现对蛋白质、DNA、RNA、小分子、药物等的检测。然而,由于生物体内许多需要检测的目标分析物浓度相对较小,对电化学DNA传感器的高灵敏度需求越来越高。因此,越来越多的人致力于发展各式各样的信号放大技术,并将信号放大方法与电化学DNA传感器相结合,提高电化学DNA传感器的检测性能。本论文通过几种不同途径实现检测信号放大,构建了几种新型信号增敏的电化学DNA传感器。论文的主要工作如下:第一章,简单介绍了传感器,电化学生物传感器,电化学DNA传感器的概念、分类、信号放大方法的重要性以及信号放大方法在电化学DNA传感器中的应用方式,并简略地概括本论文的研究内容和意义。第二章,成功制备了基于三重信号放大的新型血小板衍生生长因子-BB便携式适配体传感器。三重信号放大平台集合了纳米粒子、8-17 DNA酶CAMB循环体系以及阳离子交换反应,本实验通过转换酶间接产生可被血糖仪检测的信号,获得信号放大的便携式检测PDGF-BB的方法。第三章,描述了一个基于纳米材料放大的信号开启检测DNA甲基化酶活性的电化学方法。该实验首先利用二硫苏糖醇连接DNA-金纳米网状结构与电极,有效避免了电极与DNA溶液培养的复杂条件,同时通过网状结构负载大量信号分子,实现信号放大,灵敏检测DNA甲基化酶活性。第四章,本章通过结合催化茎环自组装形成目标物介导的循环放大,引发多个Y型DNA结构生成,携带酶信号分子接近电极表面,与碳纳米管修饰电极实现电子转移产生电化学信号,建立信号与目标物浓度的线性关系,制备了一个高效、灵敏的信号放大方法用于检测目标DNA。第五章,基于双信号比率型电化学方法,我们开发了一个新颖,简单和灵敏的电化学DNA生物传感器。在该方法中,当M.SssI甲基化酶存在时,可催化甲基化发夹DNA H1,这导致许多二茂铁接近电极表面且亚甲基蓝远离电极表面,导致了电化学信号的改变从而检测DNA甲基化酶。
[Abstract]:In recent years, electrochemical biosensor has been widely used in the field of biological analysis because of its many advantages, such as simple instrument, low cost, rapid response and high sensitivity. At the same time, because of the diverse structure, assemblage, folding and recognition of DNA, electrochemical DNA sensors are not only widely used to detect DNA damage, hybridization, but also to detect protein DNA RNA, small molecules, drugs and so on. However, because the concentration of many target analytes needed to be detected in organisms is relatively small, the high sensitivity of electrochemical DNA sensors is becoming more and more important. Therefore, more and more people are devoting themselves to develop various signal amplification techniques and combine them with electrochemical DNA sensors to improve the detection performance of electrochemical DNA sensors. In this paper, several kinds of electrochemical DNA sensors are constructed to amplify the detection signal through several different ways. The main work of this paper is as follows: in Chapter 1, the concept and classification of sensors, electrochemical biosensors, electrochemical DNA sensors are briefly introduced. The importance of signal amplification and the application of signal amplification in electrochemical DNA sensors are briefly summarized. In chapter 2, a novel platelet derived growth factor-B-B portable aptamer sensor based on triple signal amplification is successfully fabricated. The triple signal amplification platform gathers the CAMB cycle system and the cationic exchange reaction of nanocrystalline 8-17 DNA enzyme. In this experiment, a portable method for detecting PDGF-BB can be obtained by converting the enzyme into a signal that can be detected by a blood glucose meter. In chapter 3, an electrochemical method for detecting DNA methylase activity based on amplification of nanomaterials is described. In this experiment, the DNA-gold nano-network structure and electrode were connected with dithiothrenol at first, which effectively avoided the complex condition of the electrode and DNA solution culture. At the same time, the signal amplification was realized by loading a large number of signal molecules through the network structure. DNA methylase activity was detected sensitively. In chapter 4, this chapter combines the catalytic stem ring self-assembly to form a target mediated cyclic amplification, which leads to the formation of multiple Y-type DNA structures, and the molecules carrying enzyme signal are close to the electrode surface. The electrochemical signal was generated by electron transfer with carbon nanotube modified electrode, and the linear relationship between the signal and the concentration of the target was established. An efficient and sensitive signal amplification method was prepared to detect the target DNA. In chapter 5, we develop a novel, simple and sensitive electrochemical DNA biosensor based on double signal ratio electrochemical method. In this method, when M.SssI methylase exists, it can catalyze the methylation of DNA H 1, which leads to many ferrocene approaching the electrode surface and methylene blue far away from the electrode surface, resulting in the change of electrochemical signal and the detection of DNA methylase.
【学位授予单位】：安徽师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP212

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