DNA-金纳米粒子直接复合体系稳定性与可逆聚集行为研究

发布时间：2018-01-10 06:12

本文关键词：DNA-金纳米粒子直接复合体系稳定性与可逆聚集行为研究　出处：《河北大学》2017年硕士论文　论文类型：学位论文

更多相关文章： AuNPs DNA 稳定性 聚集 解聚集

【摘要】：金纳米粒子(AuNPs)由于具有独特的光、电、磁等性质,在环境、药物、食品等领域都有广泛的应用。最简单常用的制备AuNPs的方法是柠檬酸钠还原金的盐溶液。然而,该法制备的AuNPs在酸性条件或高离子强度环境中由于金纳米粒子表面电荷的改变易发生聚集。在复杂环境下保持稳定是AuNPs广泛应用的前提。获得稳定AuNPs的有效方法之一就是在制备时加入一些修饰剂对其表面进行修饰,然而这些修饰方法仍然存在一些缺点。小牛胸腺DNA具有良好的生物相容性、可降解和无毒性等特点,已经广泛应用于生物和医学领域。本文以小牛胸腺DNA为金纳米的稳定剂,采用直接复合的方法制备DNA-AuNPs直接复合体系,并研究了该复合体系在不同pH值以及不同金属离子强度的缓冲溶液中的稳定性,根据溶液颜色变化以及紫外吸收峰的改变,初步探讨了外源性因素对DNA-AuNPs直接复合体系稳定性的影响与可逆聚集行为。本论文的主要研究工作如下:pH值对DNA-AuNPs直接复合体系稳定性的影响与可逆聚集行为研究。应用紫外可见吸收光谱(UV-Vis)、原子力显微镜(AFM)、透射电子显微镜(TEM)等测试方法对AuNPs溶液进行表征。结果表明,DNA-AuNPs直接复合体系在pH为2-11的缓冲溶液中均可稳定存在,当溶液中有大量H+存在时,DNA-AuNPs直接复合体系发生聚集,加入OH-后未发生解聚集行为。在冷冻解冻循环方面,DNA修饰的AuNPs稳定性比AuNPs原溶液强。金属离子对DNA-AuNPs直接复合体系稳定性的影响与可逆聚集行为研究。结果表明,DNA-AuNPs在一定量(0-300μL)低价态金属离子(Na+、K+、Mg~(2+)、Ni~(2+))存在下具有良好的稳定性,但是加入300μL Al~(3+)、Fe~(3+)时会产生聚集,加入EDTA后聚集现象消失。
[Abstract]:Gold nanoparticles au NPs) due to their unique optical, electrical, magnetic and other properties in the environment, drugs. Food and other fields are widely used. The simplest and most commonly used method to prepare AuNPs is sodium citrate reducing gold salt solution. However. The AuNPs prepared by this method is easy to gather in acidic or high ionic strength environment because of the change of surface charge of gold nanoparticles. It is a prerequisite for the wide application of AuNPs to maintain stability in complex environment. One of the effective methods to stabilize AuNPs is to add some modifiers to modify the surface of AuNPs. However, these modification methods still have some disadvantages. Calf thymus DNA has good biocompatibility, biodegradability and non-toxicity. It has been widely used in biological and medical fields. In this paper, the direct composite system of DNA-AuNPs was prepared by using calf thymus DNA as gold nano-stabilizer. The stability of the composite system in buffer solution with different pH value and different metal ion strength was studied according to the change of the color of the solution and the change of UV absorption peak. The effects of exogenous factors on the stability and reversible aggregation behavior of DNA-AuNPs direct composite system were preliminarily discussed. The main work of this thesis was as follows:. Effect of pH value on Stability and reversible aggregation behavior of DNA-AuNPs Direct Composite system. UV-Vis absorption Spectroscopy (UV-Vis). UV-Vis. The AuNPs solution was characterized by atomic force microscopy (AFM) and transmission electron microscopy (TEM). The direct composite system of DNA-AuNPs can exist stably in buffer solution of pH 2-11. When there is a large amount of H in the solution, the direct composite system of DNA-AuNPs can aggregate. After addition of OH-, there was no deaggregating behavior, and the freezing and thawing cycle was not observed. The stability of AuNPs modified by DNA is stronger than that of AuNPs solution. The effect of metal ions on the stability and reversible aggregation behavior of DNA-AuNPs direct composite system is studied. DNA-AuNPs has good stability in the presence of a certain amount of 0 ~ 300 渭 L) low valence metal ion Na ~ (2 +) K ~ (2 +). However, when 300 渭 L Al~(3 was added, the aggregation would occur, and the aggregation would disappear after the addition of EDTA.
【学位授予单位】：河北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.1

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