碳量子点的制备及其在荧光传感器中的应用

发布时间：2017-12-30 22:10

  本文关键词：碳量子点的制备及其在荧光传感器中的应用　出处：《湖南大学》2016年硕士论文　论文类型：学位论文

  更多相关文章： 碳量子点 荧光传感器 有机磷杀虫剂 谷胱甘肽

【摘要】：荧光分析法不仅操作简单,而且响应时间快、灵敏度高、选择性好、在实时检测等方面均具有突出的优势,已被广泛应用于生物检测领域。荧光碳量子点是碳纳米材料家族的一种新型成员,近几年荧光碳量子点在各物质的生化分析检测方面得到了广泛的关注和应用。碳量子点不仅仅有优良的光学性能与小尺寸特性,而且碳量子点的毒性低生物相容性好,成为生物成像的最佳选择。因此,本研究通过制备荧光性能好的荧光碳量子点,构建了两种基于碳量子点的荧光传感器,分别实现了对氧磷、谷胱甘肽的选择性荧光分析检测。研究的主要内容概括如下：(1)碳量子点的制备方案多种多样,探索一种耗时短、合成设备简单的制备方法,对于碳量子点的研究与发展有重要的意义。第二章中采用微波加热乙二胺-柠檬酸溶液制备了氮掺杂的碳量子点(NC-dots),以组氨酸-柠檬酸作前驱体,采用水热合成法制备了碳量子点(C-dots)。利用动态光散射、红外光谱、紫外光谱、荧光光谱等多种方法对碳量子点的形貌与结构进行表征。考察了碳量子点的光稳定性与荧光量子产率,并研究了环境pH改变对碳量子点荧光强度的影响。(2)有机磷杀虫剂在人类生产中广泛应用的同时也带来了环境污染和食品安全问题,建立简单、易操作、高灵敏的有机磷杀虫剂检测方法有重要意义。第三章中,我们构建了一种基于NC-dots的荧光猝灭型传感器检测有机磷杀虫剂。NC-dots被吸附在纳米金颗粒(AuNPs)表面组装成“NC-dots壳”,NC-dots与AuNPs之间发生荧光共振能量转移(FRET),NC-dots的荧光被猝灭。乙酰胆碱酯酶(AchE)能催化底物碘化硫代乙酰胆碱(ATI)水解生成硫代胆碱,能取代AuNPs表面的NC-dots,使NC-dots解吸附随之荧光恢复。有机磷杀虫剂存在时,AChE的催化活性被抑制,NC-dots荧光恢复程度被抑制。有机磷杀虫剂的浓度可以通过NC-dots的荧光强度来定量。此传感器用于分析检测对氧磷,其灵敏度高,选择性好,对氧磷的浓度在1.0×10-4-1.0×10-9 g/L范围内,NC-dots的荧光与对氧磷的浓度之间出现了两个线性响应区间,最低检测值为1.0×10-9 g/L。该传感器能用于实际样品的检测,提供了一种快速,灵敏监测食品中有机磷含量的方法。(3)谷胱甘肽(GSH)是人体内重要的抗氧化剂和自由基清除剂,在抗衰老、抗辐射、清除自由基、解毒、保护肝脏和抗癌等方面有重要作用。第四章中,根据铜离子(Cu2+)能与C-dots生成C-dots/Cu2+的复合物猝灭C-dots的荧光,GSH与Cu2+有更强的结合能力,重新使C-dots的荧光被恢复,制备了荧光增强型传感器检测GSH。Cu2+猝灭C-dots的过程在0-80μM符合Stern-Volmer方程。经过条件优化,在最佳实验条件下,GSH的浓度在20-150μM的范围内与C-dots的荧光强度成线性关系。与现有检测方法相比,该方法操作简单,分析速度快,对GSH的检测具有特异性。
[Abstract]:The fluorescence analysis method is not only simple and fast response time, high sensitivity, good selectivity, has outstanding advantages in real-time detection, has been widely used in the field of biological detection. Fluorescent carbon quantum dots is a new member of the family of carbon nano materials, in recent years the fluorescent carbon dots has received attention and widely used in biochemical analysis and determination of each substance. CQDS not only has optical properties and excellent characteristics of small size, and low toxicity of carbon dots with good biocompatibility, become the best choice for bio imaging. Therefore, the study of fluorescent carbon quantum dots fluorescence properties through the preparation, building two a carbon fluorescence sensor based on quantum dots, were achieved by paraoxon, selective fluorescence analysis of glutathione detection. The main research contents are as follows: (1) a variety of schemes for preparation of carbon quantum dots on diversity. A cable short time, preparation method of synthesis of simple equipment, has an important significance for the research and development of carbon quantum dots. The use of microwave heating ethylenediamine citric acid solution for the second chapter carbon quantum dots doped by nitrogen (NC-dots), with histidine - citric acid as precursor, carbon quantum dots. Prepared by hydrothermal synthesis (C-dots). By using dynamic light scattering, infrared spectroscopy, UV spectroscopy, morphology and structure of fluorescence spectroscopy and other methods of carbon quantum dots were characterized. The influences of the light stability and fluorescence quantum yield of carbon quantum dots, and study the environmental impact of pH changes on the fluorescence intensity of carbon quantum dots at the same time. (2) organophosphorus insecticides are widely used in the human production has also brought environmental pollution and food safety issues, the establishment of a simple, easy to operate, has important significance of organophosphorus pesticide detection methods with high sensitivity. In the third chapter, we construct A NC-dots fluorescence quenching type sensor for the detection of organophosphorus pesticides based on.NC-dots adsorbed on gold nanoparticles (AuNPs) surface mount "NC-dots shell", fluorescence resonance energy transfer between NC-dots and AuNPs (FRET), the fluorescence of NC-dots was quenched. Acetylcholine esterase (AchE) can catalyze the substrate acetylthiocholine iodide (ATI) hydrolysis of thiocholine, can replace AuNPs NC-dots on the surface of the NC-dots desorption with fluorescence recovery. The presence of organophosphorus pesticides, the catalytic activity of AChE was inhibited by inhibition of NC-dots fluorescence recovery degree. The concentration of organophosphorus pesticides by fluorescence intensity of NC-dots. This sensor is used for quantitative detection and analysis of phosphorus oxychloride. The high sensitivity, good selectivity, paraoxon concentration of 1 * 10-4-1.0 * 10-9 in the range of g/L, the two linear response region between NC-dots fluorescence and paraoxon concentration Between the minimum detection value of 1 * 10-9 g/L. of the sensor can be used for the detection of actual samples, provides a fast and sensitive monitoring method of organic phosphorus content in food. (3) glutathione (GSH) is an important body of antioxidant and free radical scavenger, anti radiation, anti-aging, free radical scavenging. Detoxification, has an important role in protecting the liver cancer and so on. In the fourth chapter, according to the copper (Cu2+) complexes with C-dots fluorescence quenching of C-dots generated C-dots/Cu2+, GSH and Cu2+ have stronger binding ability, to make the fluorescence of C-dots was restored, the preparation process of the fluorescence enhancement type sensor for the detection of GSH.Cu2+ by C-dots in line with the Stern-Volmer equation in 0-80 M. After optimization, under the optimum conditions, the concentration of GSH fluorescence intensity in the range of 20-150 and C-dots M in a linear relationship. Compared with the existing detection method, this method operation is simple. Single, fast analysis, the detection of GSH is specific.

【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O657.3
，

本文编号：1356736