论文总字数：21245字

摘 要

自1974年Fleischmann等人发现SERS现象以来，SERS技术的理论研究和应用取得了极大发展。SERS技术在多领域都有很大价值，制备稳定、灵敏度高、可重复性好的SERS基底是SERS技术的核心和前提。本文研究在PDMS基片上制备SERS基底的方法并控制各种条件以改变银颗粒之间的间距，采用自组装法制备SERS基底，对影响银颗粒密度的各种条件作出设想并进行实验探究和验证，最终寻找SERS基底增强效果和表面银颗粒密度之间的定性关系。首先用还原剂还原AgNO₃来制备分散性较好的银胶，然后使用一种偶联剂APTMS连接PDMS表面和银胶颗粒，目的是让银颗粒均匀分布在PDMS表面。在银胶吸附到表面的过程中，有诸多条件影响颗粒的分布并决定基底表面的形貌，如银颗粒大小、PDMS浸泡银胶的时间、PDMS表面硅烷化反应的反应时间等等。采用控制变量法逐个探究这些变量的最佳条件，制备出综合性能最好的基底。最后用表面活性剂PVP缩小基底表面银颗粒的间距，对基底的SERS活性进行表征。最终得出结论，基底表面的银颗粒越密集，SERS信号越强。但当颗粒密集程度达到极限后，信号不会增强。本实验制备的基底对于SERS信号的增强以电磁增强为主。最后还发现并探究了PVP对基底性能的负面影响，发现PVP大大影响了基底表面颗粒的均匀性。

关键词：银胶，硅烷化，拉曼光谱，吸收光谱，密度

Preparation of SERS Substrate with Controllable Particle Density

Abstact

Since the SERS phenomenon was discovered by Fleischmann in 1974, great progress has been made in the theoretical research and application of SERS technology.SERS technology has great value in many fields, the preparation of stable, high sensitivity, good repeatability of the SERS substrate is the core and premise of SERS research. In this paper, we study the method of preparing SERS substrate on PDMS chip and control various conditions to change the spacing between silver particles. SERS substrate was prepared by self assembly method and solvent evaporation method. We make tentative plans and experiment research and verification on various conditions affecting the silver particle spacing,then the qualitative relationship between the enhancement effect of SERS substrate and the spacing between silver particles on the surface were finally sought. First, the Colloidal Nano-Silver was prepared by reducing AgNO₃ with the reducing agent, and then we use a coupling agent called APTMS to connect the PDMS surface and the silver colloid particles. The aim was to make the silver particles uniformly distributed on the surface of the PDMS substrate. During the process of adsorption to the surface of silver colloid, there are many factors that affect the distribution of particles and determine the morphology of the surface of the substrate, such as the reaction time of silver particle size and spacing, PDMS soaking time, PDMS silver colloid surface silylation reaction and so on. The Variable-controlling approach is used to explore the best conditions of these conditions, and the best substrate of the comprehensive performance is prepared. Finally, the surface active agent PVP is used to reduce the pitch of silver particles on the surface of the substrate, and the SERS activity of the substrate is characterized. Finally, it is concluded that the more dense the silver particles on the surface of the substrate, the stronger the SERS signal will be. But when the particle density reaches the limit, the signal will not be enhanced any more.The enhancement of SERS signal is mainly based on electromagnetic enhancement.enhancement. Finally, the negative effect of PVP on the properties of the substrate is found and explored,the uniformity of the particles on the surface of the substrate is greatly influenced by PVP.

Key words: silver colloid, silane, Raman spectrum, absorption spectrum,density

目录

摘 要 1

Abstact 2

第一章 绪 论 4

1.1拉曼散射 4

1.2表面增强拉曼散射 5

1.2.1表面增强拉曼散射的发现和进展 5

1.2.2表面增强拉曼散射原理 6

1.3几种常见的SERS活性基底及其制备方法 6

1.4表面增强拉曼散射的应用 7

第二章 SERS基底的制备及结果分析和应用 9

2.1前言 9

2.2实验部分 9

2.2.1试剂和仪器 9

2.2.2银胶的制备 9

2.2.3SERS基底的制备及变量控制 10

2.3基底SERS活性表征和结果分析 11

第三章 总结和展望 21

3.1结论 21

3.2展望 21

致谢 22

参考文献 23

第一章 绪 论

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