表面增强拉曼光谱法在测定焦磷酸根、番红花红T和汞离子中的应用

发布时间：2018-02-09 10:26

本文关键词： 表面增强拉曼光谱焦磷酸根离子番红花红T 汞离子定量　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：表面增强拉曼光谱(SERS)作为一种振动光谱技术,具有很好的分子指纹识别能力和高分析灵敏度,它的出现有效地克服了传统拉曼光谱灵敏度低的缺点。除此之外,SERS还可应用于水样的分析和现场分析,大大缩短了样品的制备和分析时间。由于这些优点,SERS广泛应用于环境检测、食品安全、生物医学和艺术考古等多种领域。本论文以银纳米粒子为基底,利用SERS技术对焦磷酸根、番红花红T和汞离子进行了测定。基于半胱氨酸(Cys)和焦磷酸根离子(PPi)之间对Cu(II)的竞争配位作用,使用Cys和罗丹明6G(R6G)修饰的银纳米粒子(Ag NPs)作为SERS基底来检测PPi。半胱氨酸通过Ag-S键连接到Ag NPs的表面,其包含的氨基酸单元可以与铜离子结合形成络合物。这导致了Ag NPs的聚集,使探针分子R6G的拉曼信号大大增强。然而,在PPi的存在下,由于PPi和Cu(II)之间的更强的络合能力,使得聚集的Ag NPs被分散,这导致SERS信号的减小,从而可以间接检测PPi。实验优化了Ag NPs的量、铜离子的浓度和混合时间等条件。该方法在0.1至80.0μM浓度范围内获得了良好的线性,检测限低至20 n M。该方法适用于加标血清样品和尿样中PPi的测定,回收率在95.2至100.5%之间,相对标准偏差4.4%。通过经典的Lee法制备出了银纳米球,并且将它们作为SERS基底来检测番红T(ST)和Hg~(2+)。ST可以通过静电相互作用吸附在Ag NPs的表面,电磁效应结合化学吸附效应使ST的拉曼信号得到了显著的增强。Hg~(2+)的存在减少了Ag NPs上吸附的ST分子,导致SERS信号的显着降低,从而能够间接检测Hg~(2+)。实验优化了包括Ag NPs的量、Na Cl的浓度、HCl的浓度、ST的浓度和反应时间等测定条件。在优化的实验条件下,ST和Hg~(2+)的线性范围分别为0.01-4.0μmol L-1和0.01-2.0μmol L-1,检测限(LOD)分别为3.0和2.0 nmol L-1。本方法随后应用于番茄酱中的ST和环境水中的Hg~(2+)的测定,加标样品中ST和Hg~(2+)的回收率分别为95.5-107.8%和91.4-110.8%。
[Abstract]:Surface enhanced Raman Spectroscopy (SERS), as a vibrational spectrum technique, has good molecular fingerprint recognition ability and high analytical sensitivity. In addition, SERS can also be used in water sample analysis and field analysis. Because of these advantages, SERS is widely used in many fields, such as environmental detection, food safety, biomedicine, art and archaeology, etc. In this paper, silver nanoparticles were used as the substrate, and pyrophosphate was studied by SERS technology. Based on the competitive coordination between cysteine cysteine (Cys) and pyrophosphate ion (PPi), The silver nanoparticles modified with Cys and Rhodamine 6G / R6G) were used as SERS substrates to detect SERS. Cysteine was bound to the surface of Ag NPs by Ag-S bond, and its amino acid units could bind to copper ions to form complexes. This led to the aggregation of Ag NPs. The Raman signal of the probe molecule R6G was greatly enhanced. However, in the presence of PPi, the aggregation of Ag NPs was dispersed due to the stronger complexation between PPi and Cu II, which resulted in the decrease of SERS signal. The results show that the amount of Ag NPs, the concentration of copper ion and the mixing time can be optimized. The method has a good linearity in the range of 0.1 渭 M to 80.0 渭 M. The detection limit was as low as 20nM.The method was suitable for the determination of PPi in serum and urine samples with recoveries of 95.2 to 100.5% and relative standard deviation of 4.4. Silver nanospheres were prepared by classical Lee method. And they are used as SERS substrates to detect the adsorption of Phanerin and Hg~(2. St on the surface of Ag NPs by electrostatic interaction, and they can be adsorbed on the surface of Ag NPs by electrostatic interaction. Electromagnetic effect combined with chemisorption effect significantly enhanced the presence of St Raman signal. Hgf2) reduced the amount of St molecules adsorbed on Ag NPs and resulted in a significant decrease of SERS signal. The determination conditions such as concentration and reaction time of sodium chloride including Ag NPs were optimized. The linear ranges of St and Hg~(2 were 0.01-4.0 渭 mol L-1 and 0.01-2.0 渭 mol, respectively. The detection limit was 3.0 and 2.0 nmol L-1, respectively. The method was then applied to the determination of St in tomato sauce and Hg~(2 in environmental water. The recoveries of St and Hg~(2 were 95.5-107.8% and 91.4-110.8%, respectively.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O657.37

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