新型荧光碳点的制备及其应用性能研究

发布时间：2018-06-04 09:27

本文选题：荧光碳点 + 掺杂　；参考：《南京理工大学》2017年硕士论文

【摘要】：荧光碳点是一种小于10nm的零维新兴碳材料,由于优异并可调的荧光性质、良好的生物相容性,在催化、生物成像、药物递送、传感和基因转染等方面具有诸多应用。在此背景下我们制备了两种荧光碳点,分别为氮、氯共掺杂的碳量子点(N,Cl-CQDs)以及聚乙烯亚胺(PEI)修饰的石墨烯量子点(GQDs-PEI)并分别研究了相关应用。荧光碳点的低量子产率限制了在一些方面的应用,针对这一问题本文提出通过元素掺杂的方式提高荧光量子产率。首先以氨基葡萄糖盐酸盐为唯一前驱体,既作为碳源又作为氮、氯元素的掺杂剂,制备出氮、氯双掺杂的荧光碳量子点。通过对反应时间和反应温度的优化,制备了荧光量子产率高达16.8%的蓝色荧光碳量子点。而后使用N,Cl-CQDs对金属离子进行检测,实验发现N,Cl-CQDs能特异性检测Fe3+。同时N,Cl-CQDs对低浓度的Fe3+(0-2 μM)仍具有良好的检测效果,检测限达到0.167 μM(R2=0.997),因此在制备传感器方面有杰出的应用前景。聚乙烯亚胺作为一种非病毒基因载体,具有高效转染的效果,然而其较高的毒性也限制了作为基因载体的可能。在本文中我们通过酰基化反应将石墨烯量子点(GQDs)表面的羧基与PEI的氨基相连接,制备了质量比为1:1,1:3和1:5的GQDs-PEI复合物并作为一种新型基因转染载体。分别使用COS7细胞以及A549细胞进行基因转染实验,发现当GQDs与PEI-1800质量比为1:3时具备最优的转染效果,转染效率分别为51%与43%,实验效果优于非病毒基因转染载体金标准PEI-25KDa的45%和35%。同时使用MTT实验测定了GQDs-PEI-1800(1:3)在COS7细胞中的毒性,发现当GQDs-PEI-1800复合物浓度达到30 μg/mL时细胞存活率仍高于85%,优于相同浓度下PEI-25KDa的细胞存活率(5%)。研究结果表明GQDs-PEI有希望发展成为一种高效低毒的基因转染载体。
[Abstract]:Fluorescent carbon spot is a kind of zero-dimensional carbon material which is smaller than 10nm. It has many applications in catalysis, bioimaging, drug delivery, sensing and gene transfection due to its excellent and adjustable fluorescence properties and good biocompatibility. In this context, we have prepared two kinds of fluorescent carbon dots, namely nitrogen, chlorine co-doped carbon quantum dots (NCl-CQDs) and polyvinylene-imide (PEI) modified graphene quantum dots (GQDs-PEI), and studied their applications. The low quantum yield of fluorescent carbon dots limits the application in some aspects. In this paper, we propose to improve the fluorescence quantum yield by doping elements. Firstly, fluorocarbon quantum dots doped with nitrogen and chlorine were prepared by using glucosamine hydrochloride as the sole precursor, both as carbon source and as a dopant of nitrogen and chlorine. The blue fluorescent carbon quantum dots with 16.8% fluorescence quantum yield were prepared by optimizing the reaction time and reaction temperature. Then the metal ions were detected by NCCl-CQDs. It was found that NCQDs could specifically detect Fe3. At the same time, NCQDs still have a good detection effect on low concentration Fe3 (0-2 渭 M), and the detection limit is 0.167 渭 m ~ (2) C ~ (2 +) 0.997N, so it has an outstanding application prospect in the preparation of sensors. As a non-viral gene vector, polyimide has high transfection efficiency. However, its high toxicity also limits the possibility of being a gene vector. In this paper, the carboxyl groups on the surface of graphene quantum dots (GQDs) were linked to the amino groups of PEI by acylation reaction. The GQDs-PEI complexes with mass ratio of 1: 1: 1: 3 and 1:5 were prepared and used as a novel gene transfection vector. COS7 cells and A549 cells were used to carry out gene transfection experiments. The results showed that when the mass ratio of GQDs to PEI-1800 was 1:3, the transfection efficiency was 51% and 43%, respectively, which was better than that of gold standard PEI-25KDa (45% and 35%). The toxicity of GQDs-PEI-1800 1: 3) in COS7 cells was determined by MTT assay. It was found that when the concentration of GQDs-PEI-1800 complex reached 30 渭 g/mL, the cell survival rate was still higher than that of 85 cells, which was better than that of PEI-25KDa at the same concentration. The results suggest that GQDs-PEI may develop into a highly efficient and low toxic gene transfection vector.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O613.71;TB383.1

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