银纳米颗粒的表面改性及SERS性能研究

发布时间：2017-12-26 18:20

本文关键词：银纳米颗粒的表面改性及SERS性能研究　出处：《中北大学》2017年硕士论文　论文类型：学位论文

【摘要】：表面增强拉曼散射(Surface Enhanced Raman Scattering,SERS)技术是一种高灵敏度、高分辨率的分析检测技术,目前已经被广泛应用到生物医学、材料科学、食品检验、环境监测等领域。随着纳米技术的发展,具有可调的表面等离子体共振特性的金属纳米颗粒衬底越来越受到各界的关注,制备出性能良好的衬底是SERS技术领域最为关键的研究内容之一。性能良好的SERS衬底不仅要有高灵敏度,还应该具备很好稳定性,本文主要针对银(Ag)纳米颗粒SERS衬底在应用过程中存在的稳定性较差的问题,围绕银纳米颗粒SERS衬底的制备和颗粒的表面改性展开,探讨表面改性对银纳米颗粒衬底的SERS活性和稳定性的影响:提出了采用核壳结构增强衬底稳定性的方法,研究了二氧化硅(SiO_2)包覆和聚氯代对二甲苯(Parylene-C)薄膜包覆的银纳米颗粒衬底的SERS活性,分析了核壳结构对银纳米颗粒衬底稳定性的增强效果。结果发现本文制备的核壳结构衬底在增强银纳米颗粒衬底的SERS活性,增加衬底稳定性或可重复利用性方面效果显著。论文首先简要介绍了纳米材料,然后探讨了采用磁控溅射工艺和退火工艺获得粒径分布均匀、纳米粒子排布致密的银纳米颗粒阵列的工艺参数,并以结晶紫分子为探针表征了银纳米颗粒阵列作为SERS活性衬底的增强作用,通过计算得到衬底的增强因子为2.15×106。本文然后采用化学气相淀积法制备得到不同二氧化硅包覆厚度的二维Ag@SiO_2核壳结构传感衬底。采用结晶紫分子为探针表征了Ag@SiO_2核壳结构衬底对拉曼信号的增强作用。实验结果表明,基于Ag@SiO_2核壳结构的SERS衬底活性随二氧化硅的包覆厚度的增加呈先增强后减弱趋势,在包覆厚度为10 nm时,衬底的SERS活性最强,其增强因子可达6.62×106,对结晶紫分子的检测限达10-12 M。在此基础上,采用去离子水浸泡实验评估了Ag@SiO_2纳米结构SERS衬底的稳定性,结果表明,浸泡在水溶液中的基于Ag@SiO_2纳米结构衬底的稳定性可由0.5 h延长至24 h,且在浸泡72 h后衬底的SERS活性的衰减幅度小于25%。针对二氧化硅包覆材料存在的可重复利用性较差的问题,采用Parylene-C薄膜对银纳米颗粒进行包覆,详细阐述了Parylene-C薄膜的沉积工艺,对比了制备过程中不同包覆厚度的Parylene-C薄膜对衬底的包覆效果和SERS活性的影响。在此基础上制备了简易的微流体沟道,并与Ag@Parylene-C纳米结构衬底集成,表征Ag@Parylene-C纳米结构衬底对拉曼信号的增强效果,以及衬底在液相环境下的稳定性。本文发现在沉积膜厚为100 nm时衬底的包覆效果好且SERS活性强,对结晶紫分子的检测限可达10-10 M,与微流体沟道集成后,衬底的可重复利用次数由20次增加到了500次,且Ag@Parylene-C纳米结构衬底的SERS活性在此过程中的衰减幅度小于10%,验证了Ag@Parylene-C纳米结构SERS基底在微流体检测应用中的可行性。
[Abstract]:Surface Enhanced Raman Scattering (SERS) technology is a highly sensitive and high-resolution analytical technology. It has been widely applied in biomedicine, material science, food inspection, environmental monitoring and other fields. With the development of nanotechnology, the surface of metal nanoparticles with tunable surface plasmon resonance has attracted more and more attentions from all walks of life. It is one of the most important research contents to prepare good performance substrates in the field of SERS technology. SERS substrate with good performance not only have high sensitivity, but also have good stability, in this paper, silver (Ag) poor stability problems in the application process of SERS nanoparticles on the substrate, the surface of silver nanoparticles SERS substrate preparation and particle modification, to investigate the effect of surface modification of silver nanoparticle substrate SERS activity and stability is proposed using core-shell structure method to enhance the stability of silica substrate, coating (SiO_2) and poly chloro-p-xylylene (Parylene-C) activity of SERS thin film coated silver nanoparticles substrate, analyzed the enhancement effect of core-shell structure on silver nanoparticles substrate stability. It is found that the core shell structure prepared in this paper is effective in enhancing SERS activity, increasing substrate stability and reusing of silver nanoparticles. The paper first briefly introduces the nano materials, and then discusses the process parameters of silver nanoparticle array with uniform particle size distribution, compact arrangement of nanoparticles obtained by magnetron sputtering and annealing process, and the crystal violet probe molecules for characterization of silver nanoparticle arrays as the enhancement of SERS activity of the substrate, the substrate through the calculation of the enhancement factor 2.15 x 106. In this paper, a two-dimensional Ag@SiO_2 core shell structure sensing substrate with different silica coating thickness was prepared by chemical vapor deposition (CVD). The crystal violet is used as a probe to characterize the enhancement of the Raman signal by the Ag@SiO_2 core - shell structure. The experimental results show that the Ag@SiO_2 core-shell structure SERS substrate with active silica coating thickness increases firstly increased and then decreased trend based on the coating thickness is 10 nm, the SERS activity of the substrate, the enhancement factor of 6.62 * 106, the detection limit of 10-12 crystal violet molecules M. On this basis, using deionized water immersion test in evaluating stability, Ag@SiO_2 nano structure SERS substrate. The results showed that soaking stability of Ag@SiO_2 nano structure substrate can be extended from 0.5 h to 24 h in aqueous solution, and after soaking for 72 h SERS active substrate attenuation rate of less than 25%. The silica coated materials are reused on the problem of the poor, silver nanoparticles were coated with Parylene-C film, describes the deposition process of Parylene-C films, influence the coating effect of SERS and the activity of Parylene-C films with different thickness of coating were compared in the process of the preparation of the substrate. On this basis, a simple microfluidic channel was fabricated and integrated with Ag@Parylene-C nanostructured substrate to characterize the enhancement effect of Ag@Parylene-C nanostructure substrate on Raman signal and the stability of substrate in liquid phase. This article found in the deposited film thickness is 100 nm when the effect of coating substrate is good and the activity of SERS, the detection limit of 10-10 crystal violet molecules M, and micro channel integration, the substrate can be reused number from 20 to 500, the attenuation rate of less than 10% SERS and Ag@Parylene-C activity in this process the nano structure of the substrate in the validation of the Ag@Parylene-C nano structure SERS substrate in the feasibility of the application in the detection of micro fluid.
【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.1

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