新型掺杂碳量子点的制备及其在分析检测和细胞成像中的应用

发布时间：2018-04-15 02:15

本文选题：掺杂 + 碳量子点　；参考：《西南大学》2017年硕士论文

【摘要】：碳量子点(carbon dots)是一种新型的荧光纳米颗粒,由于其具有很多诸如荧光稳定性好、毒性低、生物相容性高、化学性质稳定等优点,已经引起研究者的广泛关注。为了开发出一些具有特殊功能的碳量子点,研究者投入了大量的精力和时间研究新型的碳量子点,然后利用其表面丰富的官能团进行一些特异性的检测以及其它应用。近年来,研究者已经掌握了碳量子点的基本光学性质,组成结构以及其应用潜力。但是它的形成过程和发光机理还不是特别清楚,这在一定程度上限制了它的应用,因此还需要进一步探索研究。虽然关于碳量子点的报道有很多,但是种类相对较少,且其发光范围狭窄,合成种类需要进一步扩大,合成规律和机理还需要进一步的深入研究,应用领域需进一步开拓和探索。掺杂作为一种改善材料性能简单有效的方法,杂原子掺杂碳量子点能有效改善它的性能,比如荧光量子产率、发射光谱的范围、具有一些特殊的功能等。本论文主要以不同的有机分子为前驱体,通过简单的一步水热法合成不同类型的双杂原子掺杂的碳量子点,研究它们在不同条件下的稳定性以及用于离子的特异性检测和细胞的荧光成像。具体内容如下:1.以聚乙烯亚胺为氮源和4-甲酰基苯硼酸为硼源,通过一步简单的水热法合成硼、氮双掺杂发射蓝色荧光碳量子点(B/N-C-dots)。通过TEM表征,其粒径范围分布在3.7-4.7 nm很窄的范围内,平均粒径大约4.2 nm,形状类似球形,水中分散性非常好。通过和单原子掺杂相比,硼、氮双掺杂碳量子点荧光量子产率(15.85%)明显高于氮掺杂碳量子点(1.55%)和硼掺杂碳量子点(3.91%)。通过XPS和FTIR表征可知碳量子点表面有大量官能团(NH2/-COOH/-OH),并且对pH和温度表现出双重响应性。除此之外,经检测该碳量子点对Fe~(3+)具有特异响应性,考察了不同pH条件下B/N-C-dots对Fe~(3+)的选择性。通过细胞成像和细胞毒性实验表明,该碳量子点的毒性低,可用于细胞的荧光成像。2.以柠檬酸为碳源和以胱胺为氮源和硫源,通过水热法合成了氮、硫双掺杂碳量子点(N,S/C-dots),其荧光量子产率高达39.7%。所得到的碳量子点通过TEM表征,其粒径平均大小为1.7 nm,分散性很好,表面未经进一步的修饰或钝化表现出极好的水溶性。通过XPS和FTIR表征表明,碳量子点表面含有丰富的官能团。它的荧光非常的稳定,在很宽的pH(3-12)和温度范围内其荧光稳定性良好。该碳量子点可用于特异性检测重金属六价铬离子,研究了N,S/C-dots在不同条件下对六价铬离子的选择性检测。除此之外,考察了N,S/C-dots用于细胞的多色成像以及细胞毒性,表现出低毒性和良好的生物相容性。
[Abstract]:Carbon Quantum Dots (QDs) is a new type of fluorescent nanoparticles. Because of its many advantages such as good fluorescence stability, low toxicity, high biocompatibility and stable chemical properties, it has attracted the attention of researchers.In order to develop some special functional carbon quantum dots, researchers have devoted a lot of time and energy to the study of new carbon quantum dots, and then used the abundant functional groups on their surface to carry out some specific detection and other applications.In recent years, researchers have mastered the basic optical properties, composition and application potential of carbon quantum dots.However, its formation process and luminescence mechanism are not very clear, which limits its application to some extent. Therefore, further research is needed.Although there have been many reports on carbon quantum dots, there are relatively few species, and their luminescence ranges are narrow, the synthetic species need to be further expanded, and the synthesis law and mechanism need to be further studied.The application field needs further development and exploration.Doping is a simple and effective method to improve the properties of materials. Hetero-atom doped carbon quantum dots can effectively improve its performance, such as fluorescence quantum yield, emission spectrum range, and have some special functions.In this thesis, different kinds of diatomic carbon quantum dots were synthesized by a simple hydrothermal method with different organic molecules as precursors.Their stability under different conditions and their specific detection of ions and fluorescence imaging of cells were studied.The details are as follows: 1.Boron was synthesized by a simple hydrothermal method using polyethylene imine as nitrogen source and 4-formyl phenylboric acid as boron source.The TEM results show that the particle size distribution is very narrow in the range of 3.7-4.7 nm, the average particle size is about 4.2 nm, the shape is similar to the spherical shape, and the dispersion in water is very good.Compared with monatomic doping, the fluorescence quantum yield of boron, nitrogen-doped carbon quantum dots (~ 15.85) is significantly higher than that of nitrogen doped carbon quantum dots (1.55) and boron-doped carbon quantum dots (3.91%).The results of XPS and FTIR show that there are a large number of functional groups on the surface of carbon quantum dots NH _ 2 / -COOH _ (-OH) _ (-OH _ (2)), and they are double responsive to pH and temperature.In addition, the specific response of the QDs to Fe~(3 was detected, and the selectivity of B/N-C-dots to Fe~(3 at different pH was investigated.The results of cell imaging and cytotoxicity test showed that the carbon quantum dot had low toxicity and could be used in fluorescence imaging of cells. 2.Nitrogen was synthesized by hydrothermal method using citric acid as carbon source and cysteamine as nitrogen source and sulfur source.The carbon quantum dots were characterized by TEM. The average size of the QDs was 1.7 nm, the dispersion of the QDs was very good, and the surface showed excellent water solubility without further modification or passivation.The results of XPS and FTIR show that there are abundant functional groups on the surface of carbon quantum dots.Its fluorescence is very stable and has good stability in the wide pH range of 3-12) and temperature.The carbon quantum dots can be used for the specific detection of hexavalent chromium ions. The selective detection of hexavalent chromium ions under different conditions has been studied.In addition, the polychromatic imaging and cytotoxicity of NPS / C-dots were investigated, showing low toxicity and good biocompatibility.
【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O613.71;TB383.1

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