功能化荧光碳点的合成及其在重金属离子检测和细胞成像中的应用

发布时间：2018-04-16 10:04

本文选题：荧光碳点 + 荧光探针　；参考：《兰州大学》2017年硕士论文

【摘要】：相较于传统的荧光染料,荧光纳米材料既具备优良的光学稳定性和良好的生物相容性,又具有纳米材料特有的小尺寸效应、介电限域效应及宏观量子隧道效应等性质,在物理、化学、生物、医学和环境等领域具有巨大的发展潜力。近年来,荧光纳米材料的研究受到了人们的高度关注,已在化学传感、生物标记、药物运载、光电设备和光催化等领域广泛地应用。作为荧光纳米材料中重要的新成员,荧光碳点因具有良好的生物相容性、较低的细胞毒性、突出的光学性质以及良好的化学稳定性而成为研究的热点。众多研究者围绕荧光碳点合成方法的改良、发光性能的调控以及发光机理的探究等方面开展了大量工作。在前人的工作基础上,本学位论文研究工作从功能化荧光碳点的设计合成入手,通过优选反应原料和制备方法,合成了功能化的荧光碳点,并将其用于检测环境中重金属离子和生物成像等方面,并且对荧光碳点发射波长的调控进行了探索和研究,提出了一种调控碳点发射波长的新方法,将所合成的碳点用于多色细胞成像研究。本学位论文共分为4章:第一章:在大量文献的基础上,介绍了荧光纳米材料的发展背景,系统阐述了荧光碳点的性质、发光机理、制备方法及其在多个领域的应用。第二章:本章利用微波热解法,以柠檬酸和二乙烯三胺为反应物,仅用2分钟制得一种具有蓝色荧光的水溶性氮掺杂荧光碳点。该氮掺杂碳点在450 nm处发射强荧光(λex=360 nm),并且测得碳点的相对量子产率为27.7%。所合成的碳点具有优异的光学稳定性,当Hg2+离子存在时,碳点水溶液能发生明显的荧光淬灭;加入谷胱甘肽后,溶液的荧光强度明显恢复。基于此我们设计了一种“on-off-on”荧光探针用于Hg2+离子和谷胱甘肽的检测,检出限分别能达到23 nM和59 nM。此外,该氮掺杂碳点具有优异的抗疲劳性,已成功用作荧光探针来分析检测水样中的Hg2+离子,而且还实现了活细胞中Hg2+离子和谷胱甘肽的可视化检测。第三章:本章以枸杞子为原料,通过一步水热法合成了具有激发依赖性的水溶性荧光碳点。该荧光碳点在未经进一步表面修饰的情况下的相对荧光量子产率为17.2%,略高于其它以天然产物为原料制备的碳点。此外,碳点的荧光信号明显受Fe3+的影响,基于此该碳点可以作为Fe3+荧光探针,检出限可达21nM,并且实现了在实际样品和活细胞中成功检测Fe3+离子。该荧光碳点还具有激发依赖性,已成功用于活细胞的多色细胞成像。第四章:本章通过二乙烯三胺五乙酸分别与邻苯二胺、间苯二胺和对苯二胺进行水热反应合成了三种水溶性荧光碳点(o-CDs,m-CDs,p-CDs),结果发现所得碳点的荧光波长与苯二胺的结构直接相关,邻、间、对苯二胺所得碳点的荧光颜色依次为蓝、绿和红色。这说明有可能通过反应物的结构来实现碳点荧光颜色的调控。o-CDs,m-CDs和p-CDs的最佳激发波长分别是360 nm,445 nm和570 nm,最佳发射波长分别位于430 nm,510 nm和600 nm。这三种荧光碳点均已成功用于HeLa细胞的多色细胞成像,并且m-CDs能够实现细胞核的荧光标记。o-CDs,m-CDs和p-CDs在水溶液中的荧光信号对pH响应灵敏,有可能作为pH传感器用于细胞内pH水平的监测。本工作采用简单原料成功制备了不同发射颜色的荧光碳点,为实现碳点荧光颜色的调控提供了一种新思路。
[Abstract]:Compared with traditional fluorescent dyes, fluorescent nano materials possess excellent optical stability and good biocompatibility, but also has the small size effect of nanometer material characteristic, dielectric confinement effect and macroscopic quantum tunneling effect, in physics, chemistry, biology, has great potential for development of medical and environmental fields. In recent years, the research of fluorescent nanomaterials has attracted attention of the people, has been in chemical sensing, biological markers, drug delivery, application of optoelectronic devices and photocatalytic fields widely. As a new member of fluorescent nano materials, fluorescent carbon dots with good biocompatibility and low cytotoxicity. Outstanding optical properties and good chemical stability and has become a research hotspot. Many researchers focus on improvement of fluorescent carbon dots synthesis, luminescent properties and light regulation mechanism research. Has done a lot of work. Based on the previous work, the design and synthesis of research work in this dissertation from the functional fluorescent carbon dots with preparation method by optimizing the reaction material and preparation, functionalization of fluorescent carbon dots were synthesized and used for the detection of heavy metal ions in environmental and biological imaging, and regulation the emission wavelength of fluorescent carbon dots was explored and put forward a new method of controlling carbon emission wavelength, study on color cell imaging are used for the synthesis of carbon. This thesis is divided into 4 chapters: the first chapter: on the basis of a large number of literature, this paper introduces the development background of fluorescent nanomaterials the system describes the properties of fluorescent carbon dots luminescence mechanism, preparation method and its application in many fields. The second chapter: this chapter uses the microwave pyrolysis method, using citric acid and ethylene diamine two three as reactants, only 2 minutes was prepared. A blue fluorescent water-soluble nitrogen doped fluorescent carbon dots. The nitrogen doped carbon emitting strong fluorescence at 450 nm (2 ex=360 nm), and measured the relative quantum yield of carbon point synthesized 27.7%. carbon has excellent optical stability, when the presence of Hg2+ ions, carbon water solution have obvious fluorescence quenching; addition of glutathione, the fluorescence intensity was restored. Based on this we designed a on-off-on fluorescence probe for the detection of Hg2+ ion and glutathione, the detection limit can reach 23 nM and 59 nM. in addition, the nitrogen doped carbon has excellent fatigue resistance, has been successfully used as fluorescent probe to Hg2+ ion analysis of water samples, but also realize the visual detection of Hg2+ ion and glutathione in living cells. The third chapter: in this chapter, Chinese wolfberry as raw material by one-step hydrothermal synthesis has inspired by Lai of water soluble fluorescent carbon. The fluorescent carbon dots without the relative fluorescence quantum yield further surface modification for the case of 17.2%, slightly higher than the other natural products as raw materials for the preparation of carbon. In addition, effects of the fluorescence signal point carbon was significantly affected by Fe3+, this point can be used as carbon Fe3+ fluorescent probe based on the detection limit can reach 21nM, and realize the successful detection of Fe3+ ions in real samples and in living cells. The fluorescent carbon dots has excited dependence, has been successfully used in multi cell imaging of living cells. The fourth chapter two through three ethylene amine five acetic acid and benzene amine two respectively. Two, benzene amine and three kinds of water soluble fluorescent carbon dots synthesized by hydrothermal reaction of benzene amine two (o-CDs, m-CDs, p-CDs), found that directly related to the structure of the carbon dots fluorescence wavelength and two adjacent benzene amine, between the fluorescent color of two benzene amine of the carbon point in order to Blue, green and red. This shows that the structure is possible by the reactants to control.O-CDs carbon fluorescent color, optimum excitation wavelength of m-CDs and p-CDs were 360 nm, 445 nm and 570 nm, the best emission wavelengths were 430 nm, 510 nm and 600 nm. of the three kinds of fluorescent carbon dots have been success for multicolor cell imaging of HeLa cells, and m-CDs can realize the fluorescence labeled.O-CDs nuclei, the fluorescence signal of m-CDs and p-CDs in aqueous solution of pH sensitive response, can be used as a pH sensor for monitoring the intracellular level of pH. The simple material was successfully prepared different emission color fluorescent carbon dots used in this work. Provide a new way for the realization of control point carbon fluorescent color.

【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O657.3

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