不同构型二维SERS基底的制备及其检测研究

发布时间：2018-04-04 00:52

本文选题：SERS基底　切入点：自组装膜　出处：《宁波大学》2017年硕士论文

【摘要】：表面增强拉曼散射(SERS)现象能够将粗糙金属表面附近的分子的拉曼信号增加104~106倍,弥补了拉曼光谱灵敏度低的缺点,其应用依赖于SERS基底,因此发展新型SERS基底一直以来都是SERS研究领域的热点。本论文围绕SERS基底的制备和应用,开展以下工作:1.制备了具有球状结构的Ag纳米颗粒自组装膜的SERS基底,首先在硅片表面自组装上单层SiO_2@Au纳米粒子,然后通过无电沉积法在纳米粒子的表面快速生长一层银壳获得SiO_2@Au@Ag膜。我们以4-巯基吡啶为探针分子,检测限可达到10-11 M,拉曼增强因子为2.6×107,而对于单颗包裹Ag纳米颗粒的球状SiO_2粒子来说,其拉曼的检测限只有10-8M,两者的对比展示了包裹银颗粒的自组膜具有明显的SERS增强优势。然后我们将SiO_2@Au@Ag膜作为基底,检测水果表面农药的残留。只需将SiO_2@Au@Ag膜基底轻轻地在苹果表面一擦,即可进行拉曼检测,操作方便,快捷且灵敏度高。2.将分子印迹技术和表面增强拉曼技术相结合,制备了氧化石墨烯/分子印迹聚合物-探针分子-银纳米颗粒的三明治结构。在三明治结构中,氧化石墨烯为分子印迹聚合物提供了良好的结合位点,而分子印迹聚合物因其钥匙-锁的独特结构对模板分子进行选择性的吸附,而附着在上面的银纳米颗粒起到了SERS增强的作用。这种三明治结构具有良好的SERS性能和抗干扰性和选择性吸附,使用此结构对模板分子进行拉曼检测,其检测限可达到10-11 M,同时将模板分子与其他类似物进行混合时,三明治结构对模板分子进行选择性吸附,抗干扰性显著。
[Abstract]:The surface-enhanced Raman scattering (SERS) phenomenon can increase the Raman signal of the molecules near the rough metal surface by 104 ~ 106-fold, which makes up for the low sensitivity of the Raman spectrum, and its application depends on the SERS substrate.Therefore, the development of new SERS substrate has always been a hot spot in the field of SERS research.In this paper, we focus on the preparation and application of SERS substrate, and do the following work: 1.The SERS substrate of Ag nanoparticles self-assembled film with spherical structure was prepared. Firstly, monolayer SiO_2@Au nanoparticles were self-assembled on the surface of silicon wafer, and then a layer of silver shell was rapidly grown on the surface of nano-particles by electrodeposition without electrodeposition to obtain SiO_2@Au@Ag film.Using 4-mercaptopyridine as the probe molecule, the detection limit can reach 10-11 Mand the Raman enhancement factor is 2.6 脳 10 ~ 7. For a single spherical SiO_2 particle coated with Ag nanoparticles, the detection limit is 10 ~ (-11) M, and the Raman enhancement factor is 2.6 脳 10 ~ (7).The Raman detection limit is only 10 ~ (-8) M.The comparison of the two shows that the self-assembled films coated with silver particles have obvious SERS enhancement advantages.Then the SiO_2@Au@Ag membrane was used as the substrate to detect pesticide residues on the fruit surface.As long as the substrate of SiO_2@Au@Ag film is lightly rubbed on the surface of apple, Raman detection can be carried out, which is convenient, quick and sensitive.The sandwich structure of graphene oxide / molecularly imprinted polymer probe molecular silver nanoparticles was prepared by combining molecular imprinting technique with surface-enhanced Raman technique.In sandwich structure, graphene oxide provides a good binding site for molecularly imprinted polymers, while molecular imprinted polymers selectively adsorb template molecules because of their unique key- lock structure.On the other hand, the silver nanoparticles attached to it play a role in the enhancement of SERS.The sandwich structure has good SERS performance, anti-interference and selective adsorption. The Raman detection limit of the template molecule can reach 10-11 Mwhen the template molecule is mixed with other analogues.Sandwich structure can selectively adsorb template molecule, and the anti-interference property is obvious.
【学位授予单位】：宁波大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O657.37

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