几种廉价柔性SERS衬底的构筑及其对有机污染物的敏感性

发布时间：2018-03-12 08:54

本文选题：表面增强拉曼散射　切入点：柔性衬底　出处：《中国科学技术大学》2017年博士论文　论文类型：学位论文

【摘要】：高毒性的持久性有机污染物严重威胁人类生存环境与健康。因此,对其快速痕量检测至关重要。表面增强拉曼散射效应(SERS)技术具有灵敏度高、响应快和"指纹"识别等优点,在快速检测有毒污染物方面具有潜在的应用前景。应用SERS检测技术的关键是构筑高质量的SERS衬底。本文以有毒污染物的快速痕量检测为导向,采用几种柔性材料作为支撑结构负载贵金属纳米结构,构筑了几种柔性SERS衬底;并提出了一种新型的SERS检测盒器件,系统研究了柔性SERS衬底和原型器件的SERS性能及其对有毒有机污染物的SERS敏感性。本论文的主要研究内容和创新性如下:1.利用气-液界面自组装方法,制备了由单层Ag纳米立方体组成的薄膜,再将其转移到柔性透明的聚乙烯膜上,获得了 Ag纳米立方体修饰聚乙烯膜的复合SERS衬底。该柔性透明SERS衬底在大面积范围内信号均匀、稳定、重复性好和灵敏度高。尤其是该SERS衬底具有良好的透明性,入射光能从该透明SERS衬底背面穿过直接作用在Ag纳米立方体上。因此,这种柔性透明SERS衬底能直接贴在受污染的水果表面,实现了对被污染桔子表面10 pmol甲基对硫磷的快速原位检测。2.通过化学法在铜丝网上的每根铜丝的表面原位生长三维Cu(OH)2纳米线阵列,在其表面溅射修饰Ag纳米颗粒,形成Ag纳米颗粒修饰的Cu(OH)2纳米线/铜丝网分级阵列。Cu(OH)2纳米线阵列在三维空间内为贵金属纳米颗粒提供大量的负载位点,这些Ag纳米颗粒能产生大量的"热点"。因此,该SERS衬底对罗丹明R6G浓度低至0.1 pM时仍然敏感,且能快速识别10 nM的福美双分子。3.采用银镜还原法在海绵表面原位生长Ag膜,获得多孔Ag膜修饰的海绵。海绵的多孔结构能增加单位体积内的SERS活性单元。该Ag膜修饰的海绵具有很好的吸水特性,能直接浸没在待测溶液中与待测分子充分接触。利用手持式便携拉曼仪和该SERS衬底,实现了对1 nM的腺嘌呤和10 nM福美双水溶液的原位快速检测。4.利用银镜还原法在明列子的3D网络上修饰Ag纳米颗粒,获得Ag纳米颗粒修饰的明列子。将明列子的SERS基底置于器件的凹槽内,与一次性滴管结合吸取液体样品,获得滴管式SERS器件。干燥的SERS基底吸水膨胀填满凹槽空间,排出器件内多余的液体,减少了液体对入射光散射所导致的信号强度降低;同时能避免从牛奶中提取三聚氰胺的复杂步骤。采用该滴管式SERS器件,实现了快速检测牛奶中1 μ的三聚氰胺。
[Abstract]:Highly toxic persistent organic pollutants (pops) pose a serious threat to human living environment and health. Therefore, rapid trace detection is very important. Surface enhanced Raman scattering (SERS) technique has the advantages of high sensitivity, fast response and "fingerprint" recognition. It has a potential application prospect in rapid detection of toxic pollutants. The key to the application of SERS detection technology is to construct high-quality SERS substrates. This paper is directed by the rapid trace detection of toxic pollutants. Several kinds of flexible SERS substrates are constructed by using several flexible materials as supporting structures to support noble metal nanostructures, and a new type of SERS detection box device is proposed. The SERS properties of flexible SERS substrates and prototype devices and their SERS sensitivity to toxic organic pollutants are systematically studied. The main contents and innovations of this thesis are as follows: 1. Using the gas-liquid interface self-assembly method, A thin film composed of a monolayer Ag nano-cube was prepared and transferred to a flexible and transparent polyethylene film. A composite SERS substrate modified with Ag nanocrystalline cubic polyethylene film was obtained. The flexible transparent SERS substrate has the advantages of uniform signal, stable signal, good reproducibility and high sensitivity in a large area. Especially, the SERS substrate has good transparency. The incident light passes through the surface of the transparent SERS substrate directly onto the Ag nanoscale cube. Therefore, the flexible transparent SERS substrate can be directly attached to the contaminated fruit surface. The rapid in situ detection of 10 pmol methyl parathion on the surface of contaminated orange was achieved. The three-dimensional Cu(OH)2 nanowire array was grown on the surface of each copper wire on the copper wire by chemical method, and the Ag nanoparticles were modified by sputtering on the surface. The Cu(OH)2 nanowire / copper wire mesh grading array. CuOH2 nanowire array modified with Ag nanoparticles provides a large number of loading sites for noble metal nanoparticles in three dimensional space, and these Ag nanoparticles can produce a large number of "hot spots". The SERS substrate is still sensitive to the concentration of Rhodamine R6G as low as 0.1 pm, and can quickly recognize 10 nm of Formet bimolecule. Silver mirror reduction method is used to grow Ag film on sponge surface in situ. A porous Ag membrane modified sponge was obtained. The porous structure of the sponge can increase the SERS active unit in the unit volume. The Ag membrane modified sponge has a good water absorption property. Can be directly immersed in the solution to be tested in full contact with the molecules to be tested, using hand-held portable Raman spectroscopy and the SERS substrate, In situ rapid detection of 1 nm adenine and 10 nm Fu Mei aqueous solution was carried out. Silver mirror reduction method was used to modify Ag nanoparticles on the 3D network of Minglezi. The SERS substrate of the silver nanoparticles was prepared by placing the SERS substrate in the grooves of the device, and then combining with the disposable dropper to absorb the liquid sample to obtain the SERS device. The dry SERS substrate was filled with water swelling to fill the grooves. Removing excess liquid from the device reduces the signal intensity caused by the liquid scattering from the incident light, and avoids the complicated steps of extracting melamine from milk. The rapid detection of 1 渭 m melamine in milk was achieved.
【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：X830.2;O657.37

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