基于水溶性共轭聚合物和核酸适配体的生物传感体系构建及应用研究

发布时间：2018-05-17 20:18

本文选题：水溶性共轭聚合物 + 生物传感　；参考：《南京邮电大学》2016年硕士论文

【摘要】：荧光共轭聚合物具有π-π*共轭体系和高度离域化的电子结构,使其具有显著的捕捉光的能力,良好的倍增光学效果,而且还具有“分子导线”功能,可以对荧光信号进行放大。阳离子水溶性共轭聚合物,与其他荧光探针(如量子点、小分子荧光染料等)相比,具有良好的水溶性、生物相容性以及低细胞毒性,同时由于侧链带有阳离子基团,使得它可以通过静电作用,与带相反电荷的生物分子结合,发生荧光猝灭现象,被广泛的应用于生物检测、以及成像、临床医学的诊断及治疗等领域。本文旨在通过选择合适的阳离子型共轭聚合物作为荧光传感材料,以带有负电荷的生物分子(核酸适配体或三磷酸腺苷等)为分子识别元件,通过水溶性共轭聚合物的荧光猝灭和荧光恢复过程,实现对靶标分子的方便的、灵敏的、快速的、无标记检测,因此本论文的研究内容主要包含了以下3个方面:(1)基于阳离子水溶性共轭聚合物和核酸适配体,构建了一种检测肿瘤标志物的生物传感器。以阳离子型共轭聚合物作为荧光传感材料,以核酸适配体作为分子识别元件,使核酸适配体通过静电作用与共轭聚合物结合,使共轭聚合物荧光猝灭;当肿瘤标志物与核酸适配体特异性结合后,使核酸适配体离开共轭聚合物,聚合物荧光恢复,从而实现对肿瘤标志物的检测。该方法简化了探针的构建方法,能够方便检测到低水平的肿瘤标志物,而且选择性好,抗干扰性强。(2)基于阳离子水溶性共轭聚合物和核酸适配体,发展了一种检测凝血酶的生物传感器。该传感器利用了共轭聚合物的分子导线功能,以及适配体与凝血酶之间的特异性作用。凝血酶的核酸适配体通过静电作用吸附在共轭聚合物表面,使共轭聚合物发生荧光猝灭;当凝血酶与其核酸适配体结合,适配体形成G-四面体结构,增加了与共轭聚合物的距离,使得其荧光恢复,实现了对凝血酶的快速、简便的检测。(3)设计了一种简单的、灵敏的且无标记的检测三磷酸腺苷(ATP)及酸性磷酸酶的生物传感方法。以阳离子水溶性共轭聚合物作为荧光传感材料,以ATP作为猝灭剂,ATP通过静电作用与共轭聚合物结合,使共轭聚合物荧光猝灭,通过其荧光猝灭程度来判断ATP的含量;当ATP在酸性磷酸酶的作用下,发生催化水解反应,共轭聚合物的荧光会出现恢复现象。该传感体系通过阳离子型共轭聚合物的荧光猝灭及恢复的过程,实现了同时检测ATP及其酸性磷酸酶的目的。
[Abstract]:The fluorescent conjugated polymer has 蟺-蟺 * conjugated system and highly delocalized electronic structure, which makes it have a remarkable ability to capture light, has a good doubling optical effect, and has the function of "molecular conductor", which can amplify the fluorescence signal. Cationic water-soluble conjugated polymers have good water solubility, biocompatibility and low cytotoxicity compared with other fluorescent probes (such as quantum dots, small molecular fluorescent dyes, etc.), and have cationic groups in the side chain. It can be used widely in the fields of biological detection, imaging, diagnosis and treatment of clinical medicine by electrostatic action, binding with opposite charge biomolecules and fluorescence quenching phenomenon. The aim of this paper is to select a suitable cationic conjugated polymer as a fluorescent sensing material and to use negatively charged biomolecules (aptamer of nucleic acid or adenosine triphosphate, etc.) as molecular recognition elements. By fluorescence quenching and fluorescence recovery of water-soluble conjugated polymers, the detection of target molecules is convenient, sensitive, rapid and unlabeled. Therefore, this paper mainly includes the following three aspects: 1) based on cationic water-soluble conjugated polymer and aptamer of nucleic acid, a biosensor for the detection of tumor markers was constructed. Cationic conjugated polymers were used as fluorescent sensing materials and nucleic acid aptamers as molecular recognition elements. The conjugated polymers were combined with nucleic acid aptamers by electrostatic interaction to quench the fluorescence of conjugated polymers. When tumor markers are specifically combined with aptamers of nucleic acids, the aptamers of nucleic acids leave conjugated polymers and the fluorescence of polymers recovers, thus the detection of tumor markers is realized. The method simplifies the construction of the probe, and it can be used to detect low level tumor markers conveniently. Moreover, the method has good selectivity and strong anti-interference. It is based on cationic water-soluble conjugated polymers and aptamers. A biosensor for detecting thrombin was developed. The sensor utilizes the molecular traverse function of conjugated polymers and the specific interaction between the aptamer and thrombin. The nucleic acid aptamer of thrombin adsorbs on the surface of conjugated polymer by electrostatic interaction, which causes fluorescence quenching of conjugated polymer. When thrombin binds to its aptamer of nucleic acid, the aptamer forms a G-tetrahedron structure. By increasing the distance from conjugated polymer and restoring its fluorescence, a simple, sensitive and unlabeled biosensor method for the detection of adenosine triphosphate (ATP) and acid phosphatase (ACP) was designed for the rapid and simple detection of thrombin. Cationic water-soluble conjugated polymer was used as fluorescent sensing material, ATP as quenching agent combined with conjugated polymer by electrostatic interaction, and the content of ATP was determined by its fluorescence quenching degree. When ATP is hydrolyzed by acid phosphatase, the fluorescence of conjugated polymer will recover. The sensing system can simultaneously detect ATP and its acid phosphatase by fluorescence quenching and recovery of cationic conjugated polymers.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O657.3

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