不同表面修饰剂对磁性荧光纳米材料性能的影响研究

发布时间：2018-11-18 09:27

【摘要】：随着纳米科技的飞速发展,单一功能的纳米粒子在实际应用中无法满足复杂多变的需求,同时具有磁性分离和荧光标记的功能的材料成为研究热点,从而使该材料可被广泛应用于环境监测、细胞分离、标记等方面。磁性能的存在,可以很好的将材料回收再利用,不仅减小了成本,而且达到了环境友好的作用。目前如何使磁性纳米粒子与量子点复合是研究的重点,同时也要提高磁性荧光纳米粒子的生物相容性、减小粒径、保留高的磁响应性能和荧光可视性能。对磁性纳米粒子和量子点的表面修饰可以有效解决这些问题,因此对表面修饰剂选择的研究是相当的重要。对量子点修饰通常选择带有氨基、羧基或巯基的物质,用于修饰磁性纳米材料的主要分为三类:(1)无机纳米材料;(2)有机小分子;(3)有机大分子。综上可见,这是一个很有价值和应用前景的研究课题,本文因此开展了以下几个方面的研究:(1)制备量子点CdSe/CdS。在油酸和液体石蜡溶剂中,以CdO、Se和S为原料制得油相核壳CdSe/CdS,用巯基乙酸对量子点表面进行修饰,使其具有亲水性,并且表面富含羧基,便于接下来应用。结果表明量子点具有很强的荧光性,粒径大小均匀且分散较好。(2)使用有机小分子柠檬酸(CA)对Fe_3O_4磁性纳米粒子进行修饰。采用化学共沉淀法制备磁性纳米粒子,再用柠檬酸对Fe_3O_4纳米粒子进行修饰,得到Fe_3O_4/CA纳米复合粒子表面富含羧基基团,载有大量的负电荷。在乙二胺的侨联作用下,Fe_3O_4/CA纳米粒子与CdSe/CdS成功连接在一起。经过各类表征,结果表明:Fe_3O_4/CA@CdSe/CdS磁性荧光复合粒子具有很强的磁响应性和优异的荧光特性,能稳定存在,适合应用。(3)使用有机大分子甘露寡糖(MOS)对Fe_3O_4磁性纳米粒子进行修饰。以化学共沉淀法制备磁性纳米粒子Fe_3O_4,再用甘露寡糖对磁性粒子进行包裹,合成表面羟基化的Fe_3O_4/MOS,经过吸附和键合作用,与改性后的量子点连接,成功制得Fe_3O_4/MOS@CdSe/CdS磁性荧光双功能材料。对其进行表征,结果显示:该磁性荧光双功能纳米粒子,具备较好的磁响应性,荧光性能依然很好,能够稳定存在便于应用。(4)使用无机纳米材料纳米Au对Fe_3O_4磁性纳米粒子进行修饰。由于直接修饰金纳米粒子的Fe_3O_4磁性纳米粒子不能很好的直接用于生物医药等方面,利用金纳米粒子能很好的复合于含有胺基化合物,所以先用聚乙烯亚胺(PEI)改性Fe_3O_4,然后原位还原复合Au纳米粒子。再与改性后的量子点连接,得到Fe_3O_4/PEI/Au@CdSe/CdS复合粒子,表征后,结果说明:该复合材料,有着良好的磁响应性以及不错的荧光性能,同时还有Au纳米特性,在环境等领域有着很重要的应用前景。本文系统研究了三种不同类型磁性修饰剂,以及四种类型的量子点修饰剂,通过对比修饰剂对磁性荧光纳米颗粒的磁响应性能和荧光性能的影响,从而指导在实际应用中,我们可以根据对磁性和荧光不同的需要选择合适的修饰剂。
[Abstract]:With the rapid development of the nano technology, the single-function nano-particles can not meet the complex and changeable requirements in the practical application, and the material with the function of magnetic separation and fluorescent labeling has become the research hotspot, so that the material can be widely applied to environmental monitoring and cell separation, and the like. the magnetic energy exists, and the material can be recycled and reused, so that the cost is reduced, and the environment-friendly effect is achieved. At present, how to combine the magnetic nanoparticles with the quantum dots is the focus of the research, and at the same time, the biocompatibility of the magnetic fluorescent nanoparticles is improved, the particle size is reduced, and the high magnetic response performance and the fluorescence visibility property can be retained. The surface modification of the magnetic nanoparticles and the quantum dots can effectively solve these problems, so the research on the selection of the surface modifier is of considerable importance. In order to modify the magnetic nano-material, it is mainly divided into three groups: (1) the inorganic nanometer material, (2) the organic small molecule, (3) the organic macromolecule. As a result, this paper studies the following aspects: (1) the preparation of the quantum dot CdSe/ CdS. in that solvent of oleic acid and liquid paraffin, the CdSe/ CdS of the oil phase is prepared by taking CdO, Se and S as raw materials, and the surface of the quantum dot is modified with the carbon-based acetic acid, so that the CdSe/ CdS is hydrophilic, and the surface is rich in the polar base and is convenient for subsequent application. The results show that the quantum dots have strong fluorescence, uniform particle size and good dispersion. (2) Fe _ 3O _ 4 magnetic nanoparticles were modified with organic small-molecule citric acid (CA). Magnetic nanoparticles were prepared by a chemical co-precipitation method, and the Fe _ 3O _ 4 nanoparticles were modified with citric acid. In the presence of ethylenediamine, the Fe _ 3O _ 4/ CA nanoparticles were successfully connected with CdSe/ CdS. The results show that the Fe _ 3O _ 4/ CA@CdSe/ CdS magnetic fluorescent composite particles have strong magnetic response and excellent fluorescence properties, and can be stable and suitable for application. (3) The Fe _ 3O _ 4 magnetic nanoparticles were modified with organic macromannooligosaccharides (MOS). The magnetic nano-particles Fe _ 3O _ 4 were prepared by chemical co-precipitation method, and the magnetic particles were coated with mannooligosaccharides, and the surface hydroxylated Fe _ 3O _ 4/ MOS was synthesized by adsorption and bonding, and the Fe _ 3O _ 4/ MOS@CdSe/ CdS magnetic fluorescent double-functional material was successfully prepared. The results show that the magnetic-fluorescent double-functional nano-particles have good magnetic response, good fluorescence performance, and can be used stably. and (4) modifying the Fe _ 3O _ 4 magnetic nano-particles by using the inorganic nano-material nano Au. Due to the fact that the Fe _ 3O _ 4 magnetic nanoparticles of the direct-modified gold nanoparticles cannot be directly used in the aspects of biological medicine and the like, the gold nanoparticles can be well combined to contain the amine-containing compound, so that the Fe _ 3O _ 4 is modified with polyethyleneimine (PEI), and then the composite Au nanoparticles are reduced in situ. and then the modified quantum dot is connected with the modified quantum dot to obtain the Fe _ 3O _ 4/ PEI/ Au@CdSe/ CdS composite particles, and after the characterization, the composite material has good magnetic response and good fluorescence performance, and also has the Au nano-property, and has a very important application prospect in the field of environment and the like. In this paper, three kinds of magnetic modifiers, and four kinds of quantum dot modifiers, are studied. The influence of the modifying agent on the magnetic response and the fluorescence properties of the magnetic fluorescent nanoparticles is studied. We can select a suitable modifier based on the different needs for magnetism and fluorescence.
【学位授予单位】：苏州科技学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O471.1;TB383.1

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