高量子产率石墨烯量子点的制备及分析应用

发布时间：2018-03-06 22:11

本文选题：碳量子点　切入点：石墨烯量子点　出处：《安徽师范大学》2015年博士论文　论文类型：学位论文

【摘要】：荧光碳量子点(CQDs,2004年首次报道),这种零维碳纳米材料因其独特的性能一直是人们持续关注的热点。与传统的半导体量子点和荧光染料相比,水溶性好、易于功能化、耐光漂白、毒性低、生物相容性好,这些诸多优势使其在生物学和生物医学研究中越来越显示出极大的应用潜力。然而,目前制得的碳量子点在长波发射和量子产率方面存在明显不足。根据现有的文献报道,碳量子点的“发射最大波长”(即发射强度或效率最大所对应的发射波长)大都小于500nm,且荧光量子产率较低,大多数裸碳量子点都小于10%。因此,研究发展不需要复杂的钝化及后处理过程的简单方法,可控制备普适于生物成像应用的具有高荧光量子产率的近红区发射碳量子点是十分必要的。本工作主要集中在碳量子点制备的方法学研究及其生物分析应用两方面。首先,通过改进碳源氧化方式及实验条件控制,摸索了一种快速深度氧化不同碳源方法,在2-3小时反应时间快速获得了“发射最大波长”在538 nm、荧光量子产率为50%和“发射最大波长”在600 nm、荧光量子产率为18%的石墨烯量子点;并系统研究了石墨烯量子点高荧光量子产率的红光发射行为与其组成、粒径、表面态的内在联系与规律,旨在加深对碳量子点发光机制的理解。然后,基于绿光发射的石墨烯量子点的pH敏感光学性质,构建了尿素的荧光传感检测系统,并应用于血液中尿素的检测;同时,将红光发射石墨烯量子点应用于细胞成像,考察了其抗生物基质荧光干扰的性能;并将红光发射石墨烯量子点包埋于叶酸靶向脂质体中,成功实现了细胞表面叶酸受体过度表达的MCF-7细胞的靶向成像,为石墨烯量子点的靶向标记及传感提供一种简单可行的方法。论文共分为三章,具体内容如下:第一章,首先对碳量子点的性质、制备方法及应用进行综述,并在分析了荧光碳量子点的国内外研究背景及发展趋势基础上,确定了论文设想。第二章,采用高浓度硝酸,对常用硝酸氧化方法作了大的改进。以酒精灯灰为碳源,合成了高量子产率(50%)的绿光石墨烯量子点,对其形貌、组成进行相关表征,探讨其高量子产率的荧光机制。第三章,通过改换活性炭为碳源,合成高量子产率红光发射的石墨烯量子点,通过对其形貌、组成等相关表征,探讨了其高量子产率和长波发射的发光机制。第四章,研究了绿光发射石墨烯量子点的荧光性质,依据其灵敏的pH依赖荧光性质,构建了简单、灵敏的尿素荧光测定体系,并应用于人体血液中尿素的测定。第五章,将合成得到高量子产率红光发射石墨烯量子点应用于细胞成像,考察了其抗生物基底背景荧光干扰和生物相容性能第六章,基于叶酸-叶酸受体介导的靶向性,脂质体优越的生物相容性。制备了荧光石墨烯量子点叶酸靶向脂质体,通过荧光光谱和投射电镜对其进行了表征。初步实现了其靶向荧光成像。最后对本论文工作进行总结并提出下一步研究工作思路。
[Abstract]:Fluorescent carbon quantum dots (CQDs, first reported in 2004), the zero dimensional carbon nano materials because of its unique properties has been a hot spot of continuing concern. With the traditional semiconductor quantum dots and fluorescent dye, good water solubility, easy functionalization, light bleaching, low toxicity, good biocompatibility, these many advantages make it in biological and biomedical research increasingly shows great potential. However, the current carbon quantum dots prepared in the presence of long wavelength and quantum yield is obviously insufficient. According to the existing literature reports, the emission maximum wavelength of CQDS "(i.e. the emission wavelength emission intensity or maximum efficiency the corresponding) are mostly less than 500nm, and the fluorescence quantum yield is low, most of the bare carbon dots are smaller than 10%.. Therefore, the research does not require the development of simple method for complex passivation and postprocessing process, controllable preparation for students Application of NIR imaging material with high quantum yield of fluorescence emission of carbon quantum dots is very necessary. This work is focused on the methods of carbon quantum dots prepared by research and applications in biological analysis in two aspects. First, through the improvement of carbon oxidation method and experimental condition control, to find a fast oxidation different carbon source method, in 2-3 hours of fast response time obtained "emission maximum wavelength" at 538 nm, the fluorescence quantum yield of 50% and the maximum emission wavelength at 600 nm, the fluorescence quantum yield of gqds 18%; red emission behavior and studied graphene quantum dots with high fluorescence quantum yield its composition, particle size, inherent relation and regularity of surface states, to deepen the understanding of the mechanism of carbon quantum dots. Then, pH sensitive optical properties of graphene quantum dot emission based on the construction of the urea Fluorescence sensing detection system, detection and application in blood urea; at the same time, the red emission of gqds application in cell imaging, the performance of its anti biological matrix fluorescence interference was investigated; and the red emission of graphene quantum dots embedded in folate targeted liposomes, successfully targeting cell imaging the surface of the folate receptor expression of MCF-7 cells, providing a simple and feasible method for graphene quantum dots targeting and sensing. The thesis is divided into three chapters, the specific contents are as follows: the first chapter firstly, properties of carbon quantum dots, preparation method and application are reviewed, and based on the analysis of the the background and development trend of domestic and international research on the fluorescent carbon quantum dots, the conceive of the thesis. The second chapter, the high concentration of nitrate, nitric acid oxidation method to commonly used made big improvements. The alcohol lamp ash as carbon source, high quantum yield of synthesis The rate of (50%) green graphene quantum dots, the morphology, composition were characterized, and investigate the mechanism of high fluorescence quantum yield. In the third chapter, through the change of activated carbon as carbon source, graphene quantum dots synthesized high quantum yield red emission, based on the morphology, composition and other related characterization, discussed the high quantum yield and long wave emission luminescence mechanism. The fourth chapter studies the green emission fluorescence properties of graphene quantum dots, on the basis of the sensitive pH dependent fluorescence properties, constructed a simple, sensitive fluorescent urea determination system, and applied to the determination of urea in the blood of people. In the fifth chapter, the synthesis of high the red emission quantum yield of graphene quantum dots used in cell imaging, investigated the compatibility of the sixth chapter of the anti biological substrate background fluorescence and biology to based on folic acid - receptor mediated liposome target, superior biological compatibility A fluorescent graphene quantum dot folate targeted liposome was prepared. It was characterized by fluorescence and projection electron microscopy. The targeted fluorescence imaging was initially achieved. Finally, the work of this paper was summarized and the next research ideas were proposed.

【学位授予单位】：安徽师范大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：O657.3;O613.71

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