Abstract:
This work aims at the detection of the important herbicide glyphosate based on the previous modification of glyphosate in two stages and final detection by surface-enhanced Raman spectroscopy (SERS). In a first step, the affinity of glyphosate for metal plasmonic surfaces was increased by inclusion of a sulphur containing group (dithiocarbamate). In a second step, the cyclization of the latter intermediate rendered a thiazole derivative of the herbicide. The latter compound exhibits higher Raman cross section which leads to stronger SERS enhancement factors. The second step was possible thanks to the plasmon catalysis driven by metal nanoparticles, specifically silver adatoms created at the surface, and irradiated at a proper wavelength. This methodology was optimized by selecting the most appropriate experimental conditions for the chemical reactions. Density Functional Theory treatment of all the involved molecules was done in order to obtain the theoretical spectra and to identify the structural marker bands. A key goal of this work was to develop an effective system of glyphosate detection based on portable PickMolTM technology developed and patented by the SAFTRA Photonics Ltd. company to ensure an easy, quick, low cost, in-situ, and univocal detection of glyphosate in the environment.
摘要:
这项工作旨在检测重要的除草剂草甘膦的基础上,以前的改性草甘膦在两个阶段和最终检测的表面增强拉曼光谱(SERS)。第一步,通过包含含硫基团(二硫代氨基甲酸酯),草甘膦对金属等离子体表面的亲和力增加。第二步,后一中间体的环化得到除草剂的噻唑衍生物。后一种化合物表现出更高的拉曼横截面,这导致更强的SERS增强因子。第二步是可能的,这要归功于金属纳米粒子驱动的等离子体催化,特别是在表面产生的银原子,并以适当的波长照射。通过选择最适合化学反应的实验条件来优化该方法。对所有涉及的分子进行密度泛函理论处理,以获得理论光谱并鉴定结构标记带。这项工作的主要目标是开发一种有效的草甘膦检测系统,该系统基于由SAFTRAPhotonicsLtd.公司开发并获得专利的便携式PickMolTM技术,快,低成本,就地,和环境中草甘膦的明确检测。