柔性拉曼基底制备及其在环境中的应用

发布时间：2018-04-26 03:16

  本文选题：表面增强拉曼散射光谱 + PVA凝胶基底　； 参考：《西南交通大学》2015年硕士论文

【摘要】：近年来,对于表面污染物的快速现场分析检测方法的需求不断增加,比如在家庭安全和食品安全监测方面。但是目前尚且缺乏有力的表面分析测试方法从而限制了表面污染分析的发展。本文提出了一种新型的表面增强拉曼散射光谱(SERS)基底制备方法,合成的基底由于可形变的特性,可适用于各种粗糙程度的表面污染物分析。基于传统凝胶制备技术,我们利用聚乙烯醇(PVA),使其溶解于银纳米粒子(AgNPs)后与硼砂混合形成凝胶基底。我们讨论了可能影响凝胶SERS基底性能的不同影响因素,最终优化了凝胶SERS基底的制备条件,包括Ag NPs浓度,PVA浓度,PVA-Ag NPs混合物的浓缩倍数和硼砂与PVA-Ag NPs混合物的体积比。我们总结了最佳基底制备过程：首先制备5 mM Ag NPs溶液,然后将其当做溶剂溶解PVA颗粒,使得PVA的浓度为4%,然后将PVA-Ag NPs浓缩6倍,与质量分数为4%的四硼酸钠溶液以体积比为10：3的比例混合。然后,选取耐尔蓝(NBA)为探针分子,测试了PVA柔性基底对于不同材料和不同粗糙程度的材料表面的分析性能。结果发现,载玻片表面的NBA检出限为0.79pg/3cm2,另外,利用此种PVA柔性SERS基底可以检测出浓度为100 ppb的NBA(绝对量为0.79 ng/3cm2)溶液污染过后的不同的材料表面的NBA残留,包括砂纸、棉布、金属、木头等。最后,基于所制备的可形变的PVA柔性SERS基底,我们对环境中真实表面残留的农药三唑磷以及非法添加剂苏丹红Ⅲ进行了测试。利用此种凝胶基底测出的苹果、橘子、包菜表面三唑磷的最低检出限都低于国家标准水平(分别为0.2,0.2,0.1 ppm),另外,我们还测试了保存不同时间后的染色金桔表面残留苏丹红Ⅲ的含量,并用高效液相色谱法对SERS分析结果进行了验证。实验结果表明,即使是染色一个月后,金桔表面残留的亚ppb水平的苏丹红Ⅲ依然可以被快速检测出(大约2 min,包括取样时间)。由于此种分析方法并不需要样品前处理过程,因此将PVA凝胶基底和便携拉曼光谱相结合,可在食品质量保障领域得到更广泛的应用。
[Abstract]:In recent years, the demand for rapid field analysis and detection of surface pollutants, such as household safety and food safety monitoring, has been increasing. However, the development of surface pollution analysis is limited by the lack of effective surface analysis methods. A novel surface-enhanced Raman scattering (SERS) substrate is proposed in this paper. Due to its deformable properties, the synthesized substrate can be used for the analysis of surface contaminants of various rough degrees. Based on the traditional gel preparation technology, polyvinyl alcohol (PVA) was used to dissolve it in silver nanoparticles (AgNPs) and then mixed with borax to form a gel substrate. We discussed different factors which may affect the properties of gel SERS substrate, and optimized the preparation conditions of gel SERS substrate, including the concentration of Ag NPs and concentration of PVA-Ag NPs mixture and the volume ratio of borax to PVA-Ag NPs mixture. We summarize the optimal substrate preparation process: first, we prepare 5 mm Ag NPs solution, then dissolve the PVA particles as a solvent, so that the concentration of PVA is 4%, and then concentrate PVA-Ag NPs 6 times. Mixed with 4% sodium tetraborate solution at a volume ratio of 10:3. Then, the analytical properties of PVA flexible substrates for different materials and different rough materials were tested by using Nell blue PVA as probe molecule. The results showed that the detection limit of NBA on the slide surface was 0.79pg / 3cm2.In addition, the PVA flexible SERS substrate could be used to detect NBA residues on the surfaces of different materials, including sandpaper and cotton cloth, after the solution of 100 ppb (absolute amount was 0.79ng / 3cm2). Metal, wood, etc Finally, based on the deformable PVA flexible SERS substrate, the residual pesticide triazophos and the illegal additive Sudan 鈪，

本文编号：1804242