面向化学生物分子检测的自收集微引擎系统研究

发布时间：2018-05-20 20:57

本文选题：卷曲纳米技术 + 微引擎　；参考：《东南大学》2017年博士论文

【摘要】：在微型芯片上操纵并检测分子旨在实现分子检测的简便化、低成本化和高稳定性,受到生物分析、光流控等领域的研究者们的高度重视。表面增强拉曼散射(SERS)光谱利用SERS效应收集被检测分子的“指纹谱”,是一种用于探测和鉴定微量分子的有力而灵敏的分析工具。利用SERS光谱进行化学生物单分子检测,发展趋势逐渐倾向于对基底改性和与其它平台整合,实现多功能化、实用性强的一体式检测系统。本工作利用卷曲纳米技术制备多层材料的微米管,结合其几何结构并进行表面修饰,使其具有SERS特性。此外,微米管状结构可作为微引擎,成为运输分子的有效载体,用于流体中化学生物分子的收集与检测,为其在生物分析领域中提供巨大的应用潜力。论文主要工作及成果如下:1.利用卷曲纳米技术制备Au/SiO/Ti/Ag催化微引擎,多层材料的选取是为了满足多功能性的要求。使用紫外光刻或金属掩膜版的方法设计纳米薄膜的形状,并通过在特定位置引入刻蚀剂来实现纳米薄膜的定向卷曲,从而得到不同形状的微引擎。通过改变纳米薄膜的厚度来影响薄膜的应力梯度,实现Au/SiO/Ti/Ag微引擎管径的调控。此外,改变沉积纳米薄膜的衬底表面结构,可制备表面具有纳米结构的微引擎。2.由于Au本身优异的SERS活性以及催化微引擎表面粗糙的纳米结构,微引擎表现出优异的SERS特性。利用时域有限差分(FDTD)方法建立模型,对催化微引擎的表面电磁场进行模拟分析。FDTD计算表明在岛状纳米结构的“狭缝”处的电场强度最高,理论增强因子可达105。微引擎的SERS性能可以通过改变Au层的厚度或包覆增益介质来调控。3.通过改变过氧化氢浓度等参数,我们研究了催化微引擎的运动轨迹、运动速度和富集特性等行为。基于催化微引擎的微系统中测得的罗丹明6G分子的SERS信号是传统方法的约5倍,表现出微引擎系统的优越性。游动的催化微引擎作为化学生物分子的有效载体,扩展了收集分子的路径并增加了吸附分子的概率。此外,微系统中的微引擎可自主运动至收集、检测区域,相比传统的SERS检测方法属于非接触式检测,扩展了检测领域,具有光明的应用前景。
[Abstract]:Manipulating and detecting molecules on microchips is aimed at making molecular detection easier, cheaper and more stable. Researchers in the fields of biological analysis, optical flow control and so on have attached great importance to the manipulation and detection of molecules. Surface enhanced Raman scattering spectroscopy (SERS) is a powerful and sensitive analytical tool for detecting and identifying trace molecules by using the SERS effect to collect the "fingerprint spectra" of the detected molecules. Using SERS spectroscopy to detect chemical and biological monolayers, the developing trend is to modify the substrate and integrate with other platforms to realize a multi-functional and practical integrated detection system. In this work, multilayer micron tubes were fabricated by curling nanotechnology, and their geometrical structures were combined with surface modification to make them have SERS properties. In addition, the micron tubular structure can be used as a microengine and an effective carrier for the transport of molecules, which can be used for the collection and detection of chemical and biological molecules in fluid, which provides a great potential for its application in the field of biological analysis. The main work and results are as follows: 1. Au/SiO/Ti/Ag catalytic microengines were prepared by curling nanotechnology. The multilayer materials were selected to meet the multifunctional requirements. The shape of nanocrystalline films is designed by means of UV lithography or metal mask plate, and the directional curling of nanocrystalline films is realized by introducing etching agent in a specific position, so that different shapes of microengines can be obtained. By changing the thickness of the nanocrystalline film, the stress gradient of the film can be affected and the diameter of the Au/SiO/Ti/Ag microengine tube can be adjusted. In addition, by changing the substrate surface structure of the deposited nanocrystalline films, a nanostructured micro engine. 2. 2 can be prepared. Due to the excellent SERS activity of au and the rough nanostructures on the surface of the micro engine, the micro engine exhibits excellent SERS properties. The finite difference time-domain (FDTD) method is used to model the surface electromagnetic field of catalytic microengine. The FDTD calculation shows that the electric field intensity is the highest at the "slit" of the island nanostructure, and the theoretical enhancement factor can reach 105. The SERS performance of the microengine can be adjusted by changing the thickness of the au layer or coating the gain medium. By changing the concentration of hydrogen peroxide, we studied the motion trajectory, velocity and enrichment characteristics of the catalytic microengine. The SERS signal of Rhodamine 6G molecule measured in the catalytic microengine based microsystem is about 5 times that of the traditional method, which shows the superiority of the micro engine system. As an effective carrier of chemical and biological molecules, the mobile catalytic microengine extends the path of collecting molecules and increases the probability of adsorbing molecules. In addition, the micro engine in the micro system can move to the collection and detection area independently. Compared with the traditional SERS detection method, it belongs to the non-contact detection, which expands the detection field and has a bright application prospect.
【学位授予单位】：东南大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O652

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