金银纳米颗粒暗场散射成像探针在药物分析中的应用

发布时间：2018-06-21 04:16

本文选题：暗场散射成像 + 金银纳米颗粒　；参考：《西南大学》2017年硕士论文

【摘要】：暗场散射成像技术是一种对比度极高的非扫描光学成像技术,且已经被广泛地应用于生化分析、反应监测、生命过程示踪和单细胞成像等领域。单个贵金属纳米颗粒,尤其是金银纳米颗粒(AuNPs和AgNPs),由于其独特的局域表面等离子体共振(LSPR)所赋予它们的优良的光学性质,如强的紫外-可见吸收和等离子体共振散射带,通常被用作光散射探针。目前,实时监测化学反应已经成为暗场散射成像技术最为常见的应用,而尝试去监测不同类型的、用其它方法难以监测的反应无疑有着重要的意义。而且,现有的这方面研究很少涉及到与药物相关的反应,因此开展相关的研究工作将有助于拓宽暗场散射成像技术在药物分析领域中的应用范围。借助于暗场显微镜(DFM),等离子体共振能量转移(PRET)也被更好地应用于分子和离子检测,然而其机理尚未被研究清楚,包括其对距离的要求以及供受体之间可能存在的电子转移等等。此外,还未有研究基于PRET的offon模式实现对两种物质的检测,所以其应用存在一定的局限性。因此,本文在通过暗场散射成像技术监测与药物相关的化学反应以及利用PRET建立药物识别方法这两方面展开工作,具体内容如下:1.通过暗场散射成像技术实时监测农药敌百亩的动态降解过程。考虑到过度使用农药已经对环境造成了巨大的伤害,并且对食品安全构成了严重的威胁,而实时监测农药的降解动态过程中可以帮助理解并定义其降解机制,从而减少其危害。在此,以农药敌百亩(二甲基二硫代氨基甲酸钠,NaDDC)为例子,通过在暗场显微镜下成像反应中的单个AgNPs,我们实时监控了其在中性和碱性条件下的动态降解过程;其中,AgNPs的LSPR瑞利散射信号是在单个纳米颗粒水平上进行测定的。作为结果,我们推测出了敌百亩在中性和碱性条件下降解的化学机理;同时,为了了解其在不同环境下的降解过程,我们调研了金属离子,包括锌(II)离子和铜(II)离子对其降解的抑制作用。研究表明,铜(II)离子能够与敌百亩通过络合作用形成化学计量比为1:2的非常稳定的复合物,从而抑制其水解,大大降低了敌百亩的毒性。2.单个AgNPs上光致电子转移过程的可视化。理解光致电子转移(PET)的机理对于提高太阳能材料和光敏系统的光电转化效率有着重要的意义。通过利用一个LSPR光谱仪耦合的暗场显微镜在单个AgNPs上实时监测一种常见的表面增强拉曼光谱(SERS)报告分子对氨基苯硫酚(p-ATP)在光照下转变为4,4’-二巯基偶氮苯(DMAB)的化学反应,我们可视化地展现了蕴含在其中的光致电子转移过程。因p-ATP的电子转移延迟效应所造成的LSPR散射光谱的双向移动(先红移,后蓝移)揭示了反应中p-ATP的电子通过AgNPs转移到O2的路径,也使得我们能够数字化不同时间段内AgNP表面所对应的电子得失。这个可视化的PET过程提供了一种研究PET本质的简单而高效的方法,且有可能为涉及到PET的药物合成反应提供一定的理论指导。3.基于聚乙烯亚胺(PEI)修饰的金纳米棒(AuNRs)和铜离子之间的PRET的off-on模式实现对N-乙酰半胱氨酸的识别。PEI和铜离子的络合物在634 nm处有较强的吸收,而有些AuNRs的特征散射峰在630 nm附近,两者符合发生PRET的要求。因此,通过静电吸附的方式把PEI修饰到AuNRs上,利用铜离子和PEI-AuNRs之间的PRET所引起的PEI-AuNRs散射光猝灭实现对铜离子的识别;而常见药物N-乙酰半胱氨酸能够将铜离子还原成一价铜从而破坏其与PEI之间的络合作用,从而使铜离子脱离PEI-Au NRs表面并使其散射光得到恢复,以此建立N-乙酰半胱氨酸的识别方法。总之,本文以银纳米颗粒为探针,利用暗场散射成像技术可视化地监测、分析了一些用普通方法难以分析的化学反应(农药降解、光致电子转移)并推测出其反应机理,也通过PEI-AuNRs与铜离子之间的PRET的off-on模式对N-乙酰半胱氨酸进行了识别,从而拓宽了暗场散射成像技术在反应监测及药物分析中的应用范围。
[Abstract]:Dark field light scattering imaging technique is a non scanning optical imaging technology, a high contrast, and has been widely used in biochemical analysis, reaction monitoring, process tracing and single cell imaging. Single noble metal nanoparticles, especially gold and silver nanoparticles (AuNPs and AgNPs), because of its unique localized surface plasmon total Vibration (LSPR) with their excellent optical properties, such as strong UV Vis absorption and plasma resonance scattering, is often used as a light scattering probe. At present, the real-time monitoring of chemical reactions has become the most common application for dark field light scattering imaging technique, and try to monitor different types of difficult to monitor with other methods of reaction Is undoubtedly of great significance. Moreover, the existing research rarely involves associated with the drug reaction, it will help to broaden the scope of application in the dark field light scattering imaging technique in the field of drug analysis to carry out the related research work. With the help of dark field microscope (DFM), plasma resonance energy transfer (PRET) is better For the detection of molecules and ions, but the mechanism was not clear, including the distance and electron transfer may exist between donor and acceptor and so on. In addition, there is no research on the PRET based offon model to realize the detection of two kinds of material, so its application has some limitations. Therefore, through the dark scattering The chemical reaction monitoring and drug related imaging technique and the use of PRET to establish drug identification methods of the two aspects of the work, the specific contents are as follows: 1. the dynamic degradation process by dark field light scattering imaging technology for real-time monitoring of pesticide dibam. Considering the excessive use of pesticides has caused great harm to the environment, and on the food security All pose a serious threat, and the degradation dynamics of pesticides in the process of real-time monitoring can help to understand and define its degradation mechanism, so as to reduce the harm. Here, with pesticide dibam (two methyl two sodium dithiocarbamate, NaDDC) as an example, through a single AgNPs in the reaction under dark field microscope imaging, real time monitoring the The dynamic degradation process under neutral and alkaline conditions; the LSPR Rayleigh scattering signal of the AgNPs is determined at the level of individual nanoparticles. As a result, we deduced that the chemical degradation mechanism of dibam in neutral and alkaline conditions; at the same time, in order to understand the degradation process in different environments, we research the metal Ion, including zinc (II) ion and copper (II) ions on the inhibition of degradation. The results show that the copper (II) and dibam formed by complexation stoichiometry for very stable complexes of 1:2 ions can inhibit the hydrolysis, greatly reducing the toxicity of.2. single dibam visualization AgNPs photo induced electron transfer process. Solution of photoinduced electron transfer (PET) mechanism for improving the photoelectric conversion efficiency of the solar system and the photosensitive material has important significance. Through the dark field microscope using a LSPR spectrometer coupled in a single AgNPs real-time monitoring of a common surface enhanced Raman spectroscopy (SERS) data report 4-aminobenzene molecular (p-ATP) in light Change to 4,4 '- two mercapto azobenzene (DMAB) chemical reactions, we visualize which induced electron transfer process in which light. Because of the two-way mobile LSPR scattering spectra of p-ATP electron transfer delay effect caused by the (after the first red shift, blue shift) reveals the electronic reaction p-ATP transfer to O2 the path through the AgNPs, but also makes the We can gain the digital electronic different period AgNP surface corresponding to the PET. This process visualization provides a simple and efficient method to study the nature of PET, and may be involved in drug synthesis reaction of PET to provide some theoretical guidance for.3. based on polyethyleneimine (PEI) modified gold nanorods (AuNRs) and copper Ion between the PRET off-on mode of N- acetylcysteine identification.PEI and copper ion complexes have strong absorption at 634 nm, and the characteristics of some AuNRs scattering peaks near 630 nm, the two meet PRET requirements. Therefore, through electrostatic adsorption the PEI modification to the AuNRs, the use of copper ion and PEI-AuNRs PEI-AuNRs scattering quenching between PRET caused by the identification of copper ions; and common drugs of N- acetylcysteine can be reduced to copper and copper ions break the complexation between it and PEI, so that the copper ion from the PEI-Au NRs surface and the scattering light was restored, in order to establish N- acetylcysteine general Don't approach. In short, taking silver nanoparticles as probe, using dark field light scattering imaging technique and visual monitoring, analyzes some difficult to analyze by ordinary methods of chemical reactions (pesticide degradation, photoinduced electron transfer) and deduce the reaction mechanism, but also through between PEI-AuNRs and copper ion PRET off-on mode of N- acetyl cysteine The application of dark field scattering imaging technology in reaction monitoring and drug analysis is widened.
【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】：R917

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