新型表面增强拉曼光谱基底的制作与研究

发布时间：2018-06-23 02:45

本文选题：石墨烯 + 二硫化钼　；参考：《山东师范大学》2017年硕士论文

【摘要】：表面增强拉曼散射作为一种特异性的物质分析技术,由于其具有:拉曼光谱覆盖范围大,可以对无机物和有机物进行检测;水溶液影响小,可以对溶液中的物质进行分析;拉曼峰尖锐清晰,且峰强与官能团数量有关,适合进行定量分析;测试点可以精确到微米量级,可进行小范围物质分析,对样品大小形状要求低;测试过程可重复,对样品的损害低等优点,自问世就引起人们的广泛关注,现已被广泛应用与化学、生物以及环境科学等领域。但表面增强拉曼散射实验所用到的增强基底多为金、银、铜等贵金属纳米材料,基底大多合成于石英、硅片等硬质基底,这使得传统基底有以下两点不足:(1)贵金属纳米材料易于氧化,基底不易保存;(2)硬质基底无法满足物质的原位即时分析。针对以上不足,做了下列研究。(1)针对传统基底易于氧化的问题,提出了一种基于单层石墨烯和银纳米颗粒复合的新型拉曼增强基底。利用腺苷分子作为探针分子对基底性能进行检测,证明了石墨烯和银纳米颗粒复合的新型拉曼增强基底具有较高的稳定性,从而大大提高了使用寿命。相比于传统基底,复合基底的灵敏性得到提升,腺苷的最低检测浓度达到了10-7 M,拉曼信号的信噪比得到了提高,且腺苷浓度与拉曼峰强度之间有很好的线性关系,为腺苷的定量分析提供了研究思路。(2)针对传统基底易于氧化的问题,选用制备温度更低的二硫化钼作为复合材料,提出了通过热分解银纳米颗粒表面的四硫代钼酸铵制备了二硫化钼/银复合拉曼增强基底。二硫化钼/银纳米颗粒复合基底在灵敏性、信噪比、再现性、稳定性方面都展现出了良好的性能。对于罗丹明6G溶液二硫化钼/银复合拉曼增强的最低检测浓度达到10-9 M,比单一的银基底低了一个数量级。此外,拉曼强度与浓度之间有很好的线性关系。(3)针对硬质基底无法满足物质的原位即时分析的问题,利用热蒸镀技术在PET薄膜上制备一层铜膜,通过硝酸银溶液与铜膜反应制备出透明的银/铜/PET柔性基底。这种基底的制备工艺简单,适合批量化生产,我们利用罗丹明6G分子对基底的基本拉曼性能进行了表征,基底具有很高的灵敏性,检测浓度可以达到10-10 M;基底具有很好的再现性,相对标准偏差为12%。并对鱼身上的亚甲基蓝进行了原位即时检测,证明该方法制备的银/铜/PET柔性基底可以用于食品的原位即时检测。
[Abstract]:Surface enhanced Raman scattering (SERS) as a specific material analysis technique can be used to detect inorganic and organic matter because of its wide range of Raman spectra, and it can be used for analysis of substances in solution because of its small influence on aqueous solution. The Raman peak is sharp and clear, and the peak strength is related to the number of functional groups, so it is suitable for quantitative analysis. The advantages of low damage to samples have attracted much attention since they came into being, and have been widely used in chemical, biological and environmental sciences. However, the enhanced substrates used in surface-enhanced Raman scattering experiments are mostly gold, silver, copper and other noble metal nanomaterials. The substrates are mostly synthesized on hard substrates such as quartz and silicon wafers. This makes the traditional substrates have the following two shortcomings: (1) the noble metal nanomaterials are easy to oxidize and the substrates are not easy to preserve; (2) the hard substrates can not meet the in-situ analysis of materials. To solve the above problems, the following researches have been done. (1) A novel Raman enhanced substrate based on the composite of graphene monolayer and silver nanoparticles is proposed to solve the problem that traditional substrates are easy to be oxidized. By using adenosine as a probe molecule, the properties of the substrate were tested. It was proved that the novel Raman enhanced substrate with graphene and silver nanoparticles had high stability and greatly improved service life. Compared with the traditional substrate, the sensitivity of the composite substrate was improved, the minimum detection concentration of adenosine reached 10-7 Mand the SNR of the Raman signal was improved, and there was a good linear relationship between the concentration of adenosine and the intensity of the Raman peak. It provides a research idea for quantitative analysis of adenosine. (2) Molybdenum disulfide with lower temperature is selected as composite material to solve the problem that traditional substrates are easy to be oxidized. Molybdenum disulfide / silver composite Raman enhanced substrates were prepared by thermal decomposition of ammonium tetrathiomolybdate on the surface of silver nanoparticles. Molybdenum disulfide / silver nanoparticles composite substrates show good performance in sensitivity, signal-to-noise ratio, reproducibility and stability. For rhodamine 6G solution molybdenum disulfide / silver composite Raman enhanced minimum detection concentration is 10 ~ (-9) Mwhich is one order of magnitude lower than that of a single silver substrate. In addition, there is a good linear relationship between Raman intensity and concentration. (3) aiming at the problem that hard substrate can not meet the problem of in-situ analysis of materials, a copper film is prepared on PET films by thermal evaporation. A transparent silver / copper / PET flexible substrate was prepared by the reaction of silver nitrate solution with copper film. The preparation process of the substrate is simple and suitable for mass production. We have characterized the basic Raman properties of the substrate by using Rhodamine 6G molecule. The substrate is highly sensitive. The detection concentration can reach 10-10 M.The substrate has good reproducibility and the relative standard deviation is 12. In situ detection of methylene blue in fish proved that the silver / copper / PET flexible substrate prepared by this method can be used for in situ detection of food.
【学位授予单位】：山东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O657.37

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