基于单晶硅的表面有序结构构筑及其在检测中的应用

发布时间：2018-10-31 07:58

【摘要】：与体相材料相比,纳米尺度的材料由于其独特的性质而引起科研人员的浓厚兴趣,并被广泛应用在气体检测、水中污染物检测和生物检测等领域。材料表面微纳结构的构筑方法有很多种,可以分为“自下而上”和“自上而下”两类,例如纳米压印技术、刻蚀技术,都属于自上而下的方法,而无电沉积技术、物理气相沉积技术则属于自下而上的方法,结合这些加工工艺并对材料表面进行修饰,就可以产生一些独特的性能,例如金属纳米粒子可以增强材料表面的拉曼散射,毛刺状的纳米结构表面可以辅助捕获循环肿瘤细胞等,在本论文中,我们结合几种常见的微纳材料加工技术,成功构筑了几种表面有序的微纳米结构,并分别研究了它们在表面增强拉曼散射、生物检测等方面的应用。主要包括以下三个部分:一、我们提出了一种通过在热点区域构建承载平台的方法来提高表面增强拉曼散射基底的检测灵敏度。首先在硅基底上构筑悬空纳米领结结构阵列,然后真空蒸镀银,通过改变溶解银的时间来调控银纳米领结的间距,当溶解时间为150 s时,可以得到20 nm以下的间距。而胶体球之间的连接桥在溶解部分银的过程中得以保留,最终成为承载拉曼探针分子的平台,这有利于更多的拉曼探针分子落在热点区域,实现了对热点区域的充分利用,该结构具有很好的拉曼检测性能。此种定位检测物于热点区域的理念也可以用于制备其他结构,这为检测基底(不只是拉曼基底)的制备提供了一种新的方法。二、我们利用结构表面的疏水性能,采用液滴限域的无电沉积方式,以硅纳米柱为模板在硅纳米柱上表面沉积了银纳米粒子。相比于其他沉积方式,该方法沉积出来的金属粒子分散均匀,粒径可控,单个硅纳米柱上的银粒子间距小于6 nm,且成核位点被严格限制在硅纳米柱的上表面。该金属结构具有很好的拉曼重复性(RSD=3.40%)。三、我们利用直径为10μm,周期为20μm的四方排列的孔模板为掩膜,通过光刻在硅片上得到了直径为10μm的孔阵列,而后通过控制条件,在孔阵列中均匀地沉积了银纳米粒子,经过金属催化刻蚀得到了纳米孔,用超声去除一部分微米孔中的硅纳米线,浇筑PDMS,通过翻制得到了微纳复合的PDMS类仙人球结构,连接抗体后,该基底具有很好的捕获循环肿瘤细胞的性能,捕获效率为94%。PDMS材质不仅具有很好的生物相容性,且由于其表面柔软,避免了硬材料的毛刺会刺穿细胞的问题。
[Abstract]:Compared with bulk materials, nanoscale materials have attracted great interest due to their unique properties, and have been widely used in gas detection, water pollutant detection and biological detection. There are many ways to construct the micro and nano structure on the surface of materials, which can be divided into two categories: "bottom-up" and "top-down". For example, nano-imprint technology and etching technology are all top-down methods, but no electrodeposition technology. Physical vapor deposition is a bottom-up approach that combines these processes and modifies the surface of the material to produce unique properties, such as metal nanoparticles that enhance Raman scattering on the surface of the material. The surface of spine-like nanostructures can assist in capturing circulating tumor cells. In this paper, we successfully constructed several kinds of surface ordered micro-nanostructures by combining with several common micro-nano materials processing techniques. Their applications in surface enhanced Raman scattering and biological detection were studied. The main contents are as follows: first, we propose a method to improve the detection sensitivity of surface-enhanced Raman scattering substrate by constructing a bearing platform in hot spots. Firstly, an array of suspended nano-tie structures was constructed on silicon substrate, then vacuum evaporated silver plating. The spacing of silver nanorods was adjusted by changing the time of silver dissolution. When the dissolution time was 150s, the distance below 20 nm could be obtained. However, the bridging bridge between colloidal spheres was retained in the process of dissolution of some silver, and eventually became the platform for carrying Raman probe molecules, which was conducive to more Raman probe molecules falling in hot spots, and realized the full use of hot spots. The structure has good Raman detection performance. The idea of locating detects in hot spots can also be used to prepare other structures, which provides a new method for the preparation of substrates (not just Raman substrates). Secondly, we use the hydrophobicity of the structure surface to deposit silver nanoparticles on the surface of the silicon nanorods using the non-electrodeposition method in the droplet limit domain and using the silicon nanocolumn as the template. Compared with other deposition methods, the metal particles deposited by this method are uniformly dispersed, and the particle size is controlled. The spacing of silver particles on a single silicon nanocolumn is less than 6 nm, and the nucleation sites are strictly confined to the upper surface of the silicon nanocrystalline column. The metal structure has good Raman repeatability (RSD=3.40%). Third, we used a 10 渭 m tetragonal pore template with a period of 20 渭 m as a mask, and obtained a hole array of 10 渭 m in diameter by photolithography on the silicon wafer, and then uniformly deposited silver nanoparticles in the pore array by controlling the conditions. Nano-pores were obtained by metal catalytic etching, and silicon nanowires were removed from some micron holes by ultrasonic method, and PDMS, was cast to form micronano composite PDMS cactus structure, which was connected with antibody. The substrate has good performance in capturing circulating tumor cells. The capture efficiency of 94%.PDMS material is not only very good biocompatibility, but also because of its soft surface, it can avoid the problem that the burrs of hard materials will puncture the cells.
【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TQ127.2

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