基于石墨烯量子点的荧光生物传感器的应用研究

发布时间：2018-07-03 17:59

本文选题：石墨烯量子点 + G-四链体/血红素脱氧核酶　；参考：《吉林大学》2017年硕士论文

【摘要】：近年来石墨烯量子点的出现引起了人们的广泛关注,它将石墨烯与半导体量子点的优秀性能集于一身。同时这种准零维纳米材料具有显著的量子限域和边缘效应,这使得石墨烯量子点拥有较高的光致发光性能。研究发现石墨烯量子点毒性低,化学惰性强,在光致发光、水溶性、生物相容性等方面都具有良好的特性。因此,石墨烯量子点自其首次合成以来就广泛应用于细胞成像、能量储存、疾病诊断、药物传输、电化学分析或荧光生物传感。石墨烯量子点作为荧光探针,与传统的有机荧光染料相比具有独特的光学性质,如较强的信号强度,较高的量子产率,较窄的吸收峰和依赖于可调尺寸的荧光信号。以石墨烯量子点的荧光信号为基础,我们设计并提出了荧光检测或生物传感方法,在待测物浓度与石墨烯量子点光荧光信号间建立起确定的对应关系,从而通过对光信号的检测进而得出待测物的浓度。论文第一章中,首先我们分别对石墨烯量子点的基本性质、主要合成方法及其在生物医学分析领域的应用进行了阐释。其次我们介绍了G-四链体/血红素脱氧核酶的仿过氧化物酶催化活性及其对于下丘脑调节性多肽(辣根过氧化物酶)的替代作用。最后我们对本论文主要构想和研究意义进行了详细的说明。论文第二章,我们构建了一个新颖、无标记的咖啡酸荧光检测平台。检测平台的设计基于G-四链体/血红素脱氧核酶的仿过氧化物酶催化活性。实验首先以特定的DNA序列和血红素、氯化钾合成G-四链体/血红素脱氧核酶。在合成的脱氧核酶的催化下,过氧化氢被分解生成羟基自由基,羟基自由基具有较强的氧化性。然后咖啡酸被释放出的羟基自由基氧化,生成相应的醌类产物--咖啡醌。通常情况下,咖啡酸对于石墨烯量子点的荧光信号没有影响,但当咖啡酸被脱氧核酶和过氧化氢氧化后得到的咖啡醌则可以将石墨烯量子点的荧光信号有效猝灭。在最优实验条件下,体系的荧光信号强度与咖啡酸的浓度具有很好的线性相关关系,咖啡酸的线性范围为2μM~350μM,检测限为200 n M。将该方法应用于人血清样品中咖啡酸的检测时得到了令人满意的结果。论文第三章,我们构建了一个简单、高效、低毒的尿酸生物传感平台。传感平台的设计以G-四链体/血红素脱氧核酶的仿过氧化物酶催化活性和咖啡酸的引入为基础。人体中的尿酸可以被尿酸酶分解,产生过氧化氢和尿囊素。由此我们可以通过检测过氧化氢的浓度进而实现对尿酸浓度的间接检测。G-四链体/血红素脱氧核酶在室温下即可作为一种过氧化物酶将过氧化氢分解生成羟基自由基。由于羟基自由基具有强氧化性,可以将咖啡酸氧化成相应的醌类物质,使得石墨烯量子点的荧光猝灭。在最优实验条件下,体系的荧光信号强度与尿酸的浓度具有很好的线性相关关系,尿酸的线性范围为2μM~300μM,检测限为500 n M。将该方法应用于人血清样品和尿液样品中尿酸的检测时也得到了令人满意的结果。
[Abstract]:The appearance of graphene quantum dots has attracted wide attention in recent years. It combines the excellent properties of graphene and semiconductor quantum dots. Meanwhile, the quasi zero dimensional nanomaterials have significant quantum confinement and edge effect. This makes the graphene quantum dots have high photoluminescence properties. Low toxicity, strong chemical inertness, good properties in photoluminescence, water solubility, biocompatibility and so on. Therefore, graphene quantum dots have been widely used in cell imaging, energy storage, disease diagnosis, drug transmission, electrochemistry analysis or fluorescence biological sensing since their first synthesis. Graphene quantum dots are used as fluorescence probes. Traditional organic fluorescent dyes have unique optical properties, such as strong signal intensity, high quantum yield, narrow absorption peak and dependent on adjustable fluorescent signals. Based on the fluorescence signals of graphene quantum dots, we designed and proposed a fluorescence detection or biological sensing method, in which the concentration and graphite are to be measured. In the first chapter, we explain the basic properties of the graphene quantum dots, the main synthesis methods and their application in the biomedical analysis domain. Secondly, we introduce G-. The catalytic activity of four chain body / heme deoxy ribozyme and its substitution effect on the hypothalamus regulatory polypeptide (horseradish peroxidase). Finally, we gave a detailed description of the main ideas and research significance of this paper. In the second chapter, we constructed a novel and unlabeled fluorescence detection platform for caffeic acid. The design of the detection platform is based on the catalytic activity of the G- four chain body / heme deoxylase. The experiment first syntheses the G- four chain body / heme deoxribozyme with a specific DNA sequence and hemin and potassium chloride. Under the catalysis of the synthesized deoxylase, hydrogen peroxide is decomposed into hydroxyl radical, and the hydroxyl radical is stronger. Oxidation. Then the caffeic acid is released by hydroxyl radical oxidation to produce the corresponding quinone product, coffee quinone. In general, the caffeic acid has no effect on the fluorescence signals of the graphene quantum dots, but coffee quinones obtained from the oxidation of the caffeic acid after the oxidation of the deoxy ribozyme and hydrogen peroxide can signal the fluorescence signals of the graphene quantum dots. Under the optimal experimental conditions, the fluorescence intensity of the system has a good linear correlation with the concentration of caffeic acid. The linear range of the caffeic acid is 2 M~350 mu M and the detection limit is 200 N M.. The method is satisfied with the application of this method to the detection of caffeic acid in human serum samples. The third chapter of the paper has been constructed. A simple, efficient, low toxic uric acid biosensor platform. The design of the sensing platform is based on the catalytic activity of the G- four chain body / heme deoxy ribozyme and the introduction of caffeic acid. The uric acid in the human body can be decomposed by urate, producing hydrogen peroxide and allantoin. Thus, we can detect the concentration of hydrogen peroxide. .G- four chain body / heme deoxy ribozyme can be used as a peroxidase to decompose hydrogen peroxide into hydroxyl radical at room temperature. Because the hydroxyl radical has strong oxidation, it can oxidize caffeic acid to the corresponding quinone, so that the fluorescence quenching of graphene quantum dots can be quenched. Under the optimal experimental conditions, the fluorescence intensity of the system has a good linear correlation with the concentration of uric acid. The linear range of uric acid is 2 M~300 mu M, and the detection limit is 500 N M.. The application of this method to the detection of uric acid in human serum samples and urine samples has also been satisfactory.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O657.3

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