微纳结构的制备及其在表面拉曼增强光谱上的应用研究

发布时间：2018-06-27 18:06

本文选题：拉曼散射 + 表面拉曼增强光谱　；参考：《浙江大学》2016年硕士论文

【摘要】：表面增强拉曼光谱(SERS)技术具有很高的灵敏度,能够对各种低浓度分子进行检测,因此被广泛用于生物、化学和食品探测等领域。SERS增强基底的制备是实现高灵敏度探测的关键因素,而制备具有高增强效果、高稳定性以及容易制备的活性SERS基底更是一种挑战。硅纳米线阵列制备技术由于和现代集成电路工艺相兼容,使得其能够利用现有的成熟刻蚀工艺实现大批量生产。通过在硅纳米线阵列表面溅射贵金属(金、银等),就可以实现固态活性SERS基底,并且具有低成本、高灵敏度的特点。本文首先研究了拉曼散射的基本原理,并且对表面拉曼增强效应的产生机制进行了详细的介绍,并对其中物理机制和化学机制对增强效果的影响进行了分析,利用局域场增强的思想,进行模型仿真。本文详细介绍了一种改进的单层微球掩膜自组装方法,并以此制备了大面积的聚苯乙烯小球掩膜,以微球掩膜代替了传统的光刻胶工艺,简化了工艺步骤并且实现百纳米级尺度的图形刻蚀,成功制备大面积的硅纳米线有序阵列,并以此为基础,利用磁控溅射机对衬底镀金,使其能够用于拉曼增强传感测试。本文还利用时域有限差分方法,对金膜硅纳米线阵列的表面电场分布和反射率进行了分析,并结合金纳米球颗粒设计了一种新型的表面拉曼增强基底,通过电场分布和反射率曲线的对比,我们得出新型的SERS基底具有更好的局域电磁场增强,这表明基底能够产生更好的拉曼信号。在仿真的基础上,本文成功制备了这两种SERS基底,并对其测试了拉曼信号谱,通过对比相同波数下的特征峰值,从实验上验证了数值仿真的结果,证明了金纳米球与金膜硅纳米线的混合型基底具有更好的拉曼增强效果。
[Abstract]:Surface enhanced Raman spectroscopy (SERS) is widely used in biology because of its high sensitivity and the ability to detect all kinds of low concentration molecules. The preparation of SERS enhanced substrates in the fields of chemistry and food detection is the key factor to achieve high sensitivity detection. The preparation of active SERS substrates with high enhancement effect, high stability and easy preparation is a challenge. The fabrication technology of silicon nanowire array is compatible with modern integrated circuit technology, which makes it possible to use the existing mature etching process to achieve mass production. Solid active SERS substrates can be realized by sputtering precious metals (gold, silver, etc.) on the surface of silicon nanowire arrays, and have the characteristics of low cost and high sensitivity. In this paper, the basic principle of Raman scattering is studied, and the mechanism of surface Raman enhancement is introduced in detail, and the influence of physical and chemical mechanisms on the enhancement effect is analyzed. The model is simulated by using the idea of local field enhancement. In this paper, an improved self-assembly method of monolayer microsphere mask is introduced in detail, and a large area polystyrene microsphere mask is prepared. The traditional photoresist process is replaced by the microsphere mask. The process steps are simplified and the hundreds of nanoscale scale graphic etching is realized. A large area ordered array of silicon nanowires is successfully fabricated. On this basis, the substrate is gold-plated by magnetron sputtering machine, which can be used for Raman enhanced sensing testing. The surface electric field distribution and reflectivity of gold film silicon nanowire arrays are also analyzed by using finite-difference time-domain method, and a novel surface-Raman enhanced substrate is designed in combination with gold nanospheres. By comparing the electric field distribution with the reflectivity curve, we find that the new SERS substrate has better local electromagnetic field enhancement, which indicates that the substrate can produce better Raman signal. On the basis of simulation, the two SERS substrates are successfully prepared, and the Raman signal spectra are tested. The numerical simulation results are verified by comparing the characteristic peaks under the same wave number. It is proved that the mixed substrate of gold nanospheres and gold film silicon nanowires has better Raman enhancement effect.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TB383.1;O657.37

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