磁性复合纳米粒子及几种长链硫醇分子自组装单层膜的SERS研究

发布时间：2018-04-26 13:09

本文选题：SERS + 复合磁性纳米粒子　；参考：《吉林大学》2017年硕士论文

【摘要】：表面增强拉曼散射(SERS)光谱作为分子与基底结构信息检测的一种技术手段,具有高选择性和高灵敏度等特点。其增强机理一般认为主要有两种:电磁场增强机理和化学增强机理。两种增强机理都必须考虑基底的作用,贵金属的纳米溶胶是SERS的传统基底。随着技术的不断发展,许许多多不同的基底也被提出,而复合磁性纳米材料由于具有良好的生物相容性等特有性质的同时,还易于形成“热点”,用作基底可以提供更好的SERS活性,用途广泛。在这篇论文中,利用聚二烯二甲基氯化铵(PDDA)、三甲氧基硅(APTMS)分别制备了Fe_3O_4@SiO_2@Au/Ag磁性复合纳米粒子,选出了最优的磁性纳米粒子,考察了其SERS活性,并应用于一些蛋白质的检测中。利用SERS对正己硫醇(HT),正辛硫醇(OT),正癸硫醇(DT),正十二烷基硫醇(DDT)等长链烷基硫醇分子在银基底表面的吸附和组装过程进行了研究。主要的研究内容如下:(1)复合磁性纳米粒子构筑热点的SERS光谱研究论文通过溶剂热法制备了前驱体Fe_3O_4纳米颗粒,利用PDDA、APTMS分别制备了Fe_3O_4@SiO_2@Au/Ag磁性复合纳米粒子。通过透射电子显微镜(TEM)、紫外可见吸收光谱(UV-vis)、磁滞回线等各种测试手段对复合材料进行了系统表征。实验数据显示,Au、Ag NPs被成功连接到修饰过的Fe_3O_4纳米粒子表面。在外加磁场作用下,复合材料有良好的磁响应行为,利用其磁性能,可以通过外加磁场改变复合材料的聚集状态,从而提高粒子的SERS活性。重点考查了复合材料的SERS活性,分别以聚二烯二甲基氯化铵(PATP)和4-巯基苯甲酸(4-MBA)为探针分子研究该复合基底的性能,验明该基底具有很好的SERS灵敏度,得出由PDDA偶联Au和Fe_3O_4@SiO_2得到Fe_3O_4@SiO_2@Au磁性复合纳米粒子具有更强的SERS活性。将该基底应用于蛋白质分子HRP、lysozyme和Atto 610标记蛋白的检测中,检测效果良好。(2)几种长链硫醇分子自组装单层膜的SERS光谱研究论文利用SERS光谱研究了对正己硫醇(HT)、正辛硫醇(OT)、正癸硫醇(DT)和正十二烷基硫醇(DDT)四种分子分别吸附在银纳米粒子表面的结构,探究了浓度对吸附过程的影响。实验中,通过对SERS谱图反式和旁式相关的振动峰的分析发现,较高浓度下,吸附6小时后,这几种长链烷基硫醇分子形成的单层膜都具有很高的有序性,随着浓度降低,有序性逐渐降低。实验还发现,四种分子中,随着链长增长,分子在银纳米粒子表面的吸附越来越少,而6个碳的HT,由于链长合适,吸附量最大。对正己硫醇(HT)、正辛硫醇(OT),正癸硫醇(DT)和正十二烷基硫醇(DDT)成膜动力学规律的研究为单层膜制备奠定了良好的基础,未来在器件、防腐和生物等方面的应用具有一定的意义。
[Abstract]:Surface enhanced Raman scattering (SERS) spectroscopy is a technical means for the detection of molecular and basal structure information. It is characterized by high selectivity and high sensitivity. Its enhancement mechanism is generally believed to have two main types: electromagnetic enhancement mechanism and chemical enhancement mechanism. The two enhancement mechanisms must consider the role of the substrate and the nanossols of precious metals As the traditional basement of SERS, with the continuous development of technology, many different substrates have also been proposed, and the composite magnetic nanomaterials are also easy to form "hot spots" because of their good biocompatibility and other characteristics, which can provide better SERS viability and wide use. In this paper, the use of polydiene is used. Fe_3O_4@SiO_2@Au/Ag magnetic composite nanoparticles were prepared by two methyl ammonium chloride (PDDA), trimethoxy silicon (APTMS), and the best magnetic nanoparticles were selected. Their SERS activity was investigated and applied to the detection of some proteins. Using SERS for hexyl mercaptan (HT), n-octyl mercaptan (OT), n-decyl mercaptan (DT), and positive twelve alkyl mercaptan (DDT), etc. The adsorption and assembly process of long chain alkyl mercaptan on the surface of silver substrate have been studied. The main contents are as follows: (1) SERS spectroscopy study on the hot spots of composite magnetic nanoparticles, the precursor Fe_3O_4 nanoparticles were prepared by solvothermal method, and Fe_3O_4@SiO_2@Au/Ag magnetic composite nanoscale was prepared by PDDA and APTMS The composites were systematically characterized by transmission electron microscopy (TEM), ultraviolet visible absorption spectroscopy (UV-vis) and hysteresis loop. The experimental data showed that Au and Ag NPs were successfully connected to the surface of modified Fe_3O_4 nanoparticles. Under the effect of applied magnetic field, the composites have good magnetic response behavior. The magnetic properties of the composite can be changed by the magnetic field and the SERS activity of the composite can be improved. The SERS activity of the composite is examined emphatically. The properties of the composite substrate are studied with polydiene two methyl ammonium chloride (PATP) and 4- mercapto benzoic acid (4-MBA) as the probe molecules. The results show that the substrate has a good SERS sensitivity. It is concluded that the Fe_3O_4@SiO_2@Au magnetic composite nanoparticles have stronger SERS activity by PDDA coupling Au and Fe_3O_4@SiO_2. The application of this substrate to the detection of protein molecules HRP, lysozyme and Atto 610 labeling proteins is good. (2) SERS spectra of several long chain mercaptan self assembled monolayers using SERS light The structure of four molecules, n-hexyl mercaptan (HT), n-octyl mercaptan (OT), n-decyl mercaptan (DT) and twelve alkyl mercaptan (DDT), was studied respectively. The effect of concentration on the adsorption process was investigated. In the experiment, the adsorption of SERS spectra and the vibration peaks related to the side formula showed that the adsorption was 6 hours at a higher concentration. After that, the monolayers of these long chain alkyl mercaptan molecules have very high ordering. With the decrease of concentration, the order of order gradually decreases. In the four molecules, the adsorption of the molecules on the surface of silver nanoparticles is less and less with the growth of the chain length, and the HT of 6 carbon is the most suitable for the chain length. For hexyl alcohol (HT), The study on the film dynamics of n-octyl (OT), n-decyl mercaptan (DT) and twelve alkyl mercaptan (DDT) has laid a good foundation for the preparation of single layer membrane. It has a certain significance in the future applications of devices, anticorrosion and biology.

【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.1;O657.37

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