基于AAO模板法的Ag纳米棒阵列的精细调控及其SERS响应特性研究

The key issue of Surface Enhanced Raman Scattering (SERS) technique is to devolop a SERS active substrate which is highly uniform, highly controllable and with a high senstivity. The aim of this proposal is to fabricate regularly arranged, interspace and aspect ratio controllabe Ag nanorod arrays, which can also be tuned with the preferential growth orientation and the crystallinity of the nanowires on the supporting substrate. By incorporating anodic aluminum oxide (AAO) template which is highly ordered and pulsed electrodeposition method which has many prameters can be tuned, the structure of the Ag nanorod arrays will be finely tuned. The influence of the interspace, the aspect ratio, the preferential growth orientation and the crystallinity of nanowires to the SERS signal of target molecule will be studied. The corresponding relationship between the structure prameters and the SERS activity of the array will be especially regarded. As a result, the characteristic structure parameters of a highly SERS active Ag nanorod array substrate will be obtained and they will be the standard to the design of a optimal SERS active Ag nanorod array substrate which has fixed interspace, fixed aspect ratio, fixed preferential growth orientation and fixed crystallinity. The growth of this optimized substrate will be realised by thoroughly adjusting the experimental parameters. The optimized substrate will be used to the detection of trace amount TNT molecules. This study will provide a theoretical and experimental support for the fine controllable growth of 1D noble metal nanoarray SERS active substrate based on AAO template method. The controlling growth route developed will provide a solid basis for the application of noble metal array based SERS detection method.

开发结构均一、可控性强、灵敏度高的活性基底是SERS技术发展的关键。本项目利用结构周期高度有序的氧化铝模板与技术参数可调的脉冲电化学沉积相结合的方法，在支撑衬底上精细调控制备排列规则、间距可控、长径比可控、阵列择优生长取向可控以及结晶性可控的Ag纳米棒阵列结构。研究纳米棒间距、长径比、择优生长取向以及结晶性对目标分子SERS信号的影响，探索各个结构参数与基底SERS活性强弱的对应关系，得出具有高SERS活性的Ag纳米棒阵列基底的特征结构参数。以此为指导，综合调控各项实验参数制备具有最优结构（确定间距、确定长径比、确定择优生长取向、确定结晶性）的Ag纳米棒阵列 SERS基底，实现对TNT分子的痕量检测。本研究将为AAO模板法精细调控制备高SERS活性的一维贵金属纳米阵列基底提供实验和理论支持，为贵金属纳米阵列SERS活性基底的应用奠定基础。

TNT是一种典型的硝基爆炸物，表面增强拉曼散射光谱以其灵敏度高、可提供丰富的分子结构信息等优点，成为一种定性、定量检测TNT的有力工具。本项目通过构建Ag纳米棒阵列SERS基底来达到对痕量TNT的检测，在实际过程中通过氧化铝模板与电化学沉积相结合的方法优化阵列结构，实现了对10-4 M pATP及18.2 ppm DNT的检测。在此基础上，尝试了新型SERS基底和结构参数探索，包括溶胶-凝胶法制备银纳米三角片、银纳米球、银纳米立方块及相应的最大电磁场强度的有限元模拟计算，发现滤纸负载银纳米三角片得到的SERS基底具有高度SERS活性，能够实现对10-8 M pATP及10-6 M PA的检测。此外，合适参数的硅纳米线阵列负载银颗粒基底能够实现10-11 M TNT的检测。为了实现爆炸物的实际探测，在气氛TNT检测的新理论、新方法和新材料探索方面做出了有力的尝试，包括光电检测硝基爆炸物蒸气的理论认识、基于荧光纳米网状纤维膜的硝基爆炸物蒸气检测、气敏方法检测硝基爆炸物等方面。通过项目实施，获得了检测痕量TNT的新材料3种，能够实现对TNT的选择性、识别性检测。本项目的实施为开发新的爆炸物检测方法、传感材料设计做出了有力尝试和探索。