以DNA为模板的纳米粒子的自组装以及表面增强拉曼的研究

发布时间：2018-04-08 22:21

本文选题：DNA　切入点：纳米粒子　出处：《北京化工大学》2015年硕士论文

【摘要】：DNA是至关重要的遗传物质,它的反相平行双螺旋结构模型的发现开启了分子生物学领域的新的一页。然而,除去其作为遗传物质的角色,DNA凭借其特殊的化学,生物特性使其在纳米材料科学以及药物靶向治疗方面也有很大的潜力。随着几十年DNA研究的进一步发展,DNA纳米技术作为新兴的纳米技术被用来构造二维甚至是三维的纳米结构,为人类展现了一个丰富多彩的,无与伦比的纳米世界。在纳米尺度的组装上,构筑基元的结合位点的选择很重要,根据实验思路,设计较近或者较远距离对得到的组装体的光学性能有很大的影响。因而,在DNA组装的研究中,如何精确地控制组装结合位点,得到可调控的光电信号是一个难题。DNA折纸术(DNA Origami)的出现,提供了解决这个挑战的有效方法。DNA Origami是一种独特的组装方法,根据预先设计的结构,将长链与众多短链混合到一起,短链就如图订书钉链将长链折成想要的结构。这种新颖的方法,具有可预先设计位点,生物相容性好,可组装物质多样等优势。因此,DNA Origami以其精确可设计调控位点,化学计量准确,产物结构易纯化等优势成为了研究的新热点。贵金属纳米粒子与DNA Origami组装可预先精确设计调控位点,从而更好地调控光学信号的强弱,贵金属纳米粒子与折纸结构组装后,会引发更强的表面等离子共振现象,也就是表面增强拉曼(SERS)。一直以来,DNA引导的自组装涉及的组装尺寸都较小,多是纳米尺寸,在介观,乃至宏观领域的研究较少。但是,DNA精确的碱基配对原则是很多超分子物质所不具备的,因此将DNA引导的自组装扩展到介观领域迫在眉睫。本论文第二、三章利用DNA的独特的碱基互补配对,将纳米粒子定点组装到DNA折纸结构上,实现了纳米粒子在指定位置精确组装。通过引入特征拉曼分子得到结构信号可控的表面增强拉曼结构。拉曼信号提高102倍并且在金纳米粒子组装体的基础上更换银纳米粒子,使表面增强拉曼信号进一步提高103倍,可应用于结构检测,分析等领域。论文第四章创新地利用DNA引导玻璃纤维与石英片基底组装,并在磁场操控条件下得到较复杂图案,成功将DNA引导的组装延伸到介观领域,为进一步将DNA引导的组装应用到更大尺寸奠定了良好的基础。本论文主要分为三个部分：1.系统介绍了DNA Origami的经典模型以及在纳米医药生物领域的研究与应用；2.将贵金属纳米粒子(金,银)组装DNA Origami上,通过调控位点,得到三维组装体,引入拉曼特征分子,得到表面增强拉曼结构;3.在玻璃纤维表面组装磁性纳米粒子(MNPs)多层膜,之后再将基底与玻璃纤维同时修饰互补DNA序列,通过磁铁引导玻璃纤维运动,使其固定在基底表面,并得到较为复杂的组装图案。
[Abstract]:DNA is the most important genetic material, and the discovery of its inverse parallel double helix structure model opens a new page in the field of molecular biology.However, the removal of its role as genetic material makes DNA have great potential in nanomaterials science and drug targeting therapy because of its special chemical and biological properties.With the further development of DNA research in recent decades, as a new nanotechnology, DNA nanotechnology has been used to construct two-dimensional or even three-dimensional nanostructures, showing us a colorful and unparalleled nanometer world.In nanoscale assembly, the selection of binding sites for building units is very important. According to the experimental ideas, the optical properties of the assembled materials are greatly affected by the design of closer or longer distance.Therefore, in the research of DNA assembly, how to precisely control the assembly binding site and obtain the controllable photoelectric signal is a difficult problem.Origami is a unique assembly method. According to the pre-designed structure, the long strands are mixed with many short strands, and the short strands are like the long strands that are folded into the desired structures.This novel method has the advantages of predesigned sites, good biocompatibility and various assembly materials.Therefore, Origami has become a new research hotspot for its advantages of precise design of regulatory sites, accurate stoichiometry and easy purification of product structures.The assembly of noble metal nanoparticles with DNA Origami can accurately design the control sites in advance, so as to better control the intensity of optical signals. After the assembly of noble metal nanoparticles and origami structures, it will lead to a stronger surface plasmon resonance phenomenon.This is surface-enhanced Raman spectroscopy.DNA guided self-assembly has been involved in small size, mostly nanoscale size, and less research in mesoscopic and even macro fields.However, the principle of exact base pairing is not available in many supramolecular materials, so it is urgent to expand the self-assembly of DNA to mesoscopic field.In the second and third chapters, the unique base complementary pairing of DNA is used to assemble the nanoparticles onto the origami structure of DNA.Surface enhanced Raman structures with controllable structural signals are obtained by introducing characteristic Raman molecules.The Raman signal is increased 102 times and the silver nanoparticles are replaced on the basis of the gold nanoparticles assembly. The surface enhanced Raman signal can be further enhanced by 103 times. It can be used in structure detection, analysis and other fields.In chapter 4, DNA is used to guide glass fiber and quartz substrate assembly, and complex patterns are obtained under the condition of magnetic field control. The DNA guided assembly is successfully extended to mesoscopic field.It lays a good foundation for further application of DNA-guided assembly to larger size.This paper is divided into three parts: 1.The classical model of DNA Origami and its research and application in the field of nanometer medical biology are introduced systematically.The noble metal nanoparticles (gold, silver) were assembled on DNA Origami. Three-dimensional assembly was obtained by controlling the sites, and Raman characteristic molecules were introduced to obtain surface-enhanced Raman structure.The magnetic nanoparticles (MNPs) multilayer film was assembled on the surface of glass fiber, and then the substrate and glass fiber were modified with complementary DNA sequence simultaneously. The motion of glass fiber was guided by magnets and fixed on the substrate surface, and a more complex assembly pattern was obtained.
【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1

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