基于贵金属反蛋白石结构的表面增强拉曼散射效应快速检测农药残留

The pesticide residues in vegetables have been seriously harming human health. The detection of such chemicals based on conventional techniques is generally time-consuming. Surface-enhanced Raman scattering (SERS) technique can be used to rapidly and accurately detect trace amount of organics. Recently, it is still a challenge to realize highly sensitive and reliable detection of pesticide residues based on SERS effect. In this project, we will fabricate SERS substrates with high SERS-activity, high SERS-signal reproducibility and a capability to capture pesticide residue molecules. We construct highly ordered noble metal inverse opal structure SERS substrate based on ordered polystyrene sphere template-assisted electrodeposition. The highly ordered template-assisted fabrication approach can ensure high SERS-signal reproducibility, and hence the detection results are high reliable. By appropriate surface modification, the inverse opal structure is capable of capturing pesticide residue molecules by interactions such as van der Waals force. The inverse opal structure has close-packed noble metal secondary nanostructures, which can provide high-density three-dimensionally distributed SERS “hot spots” and high SERS activity; and thus the inverse opal structure shows high SERS sensitivity to the captured pesticide residue molecules. The rapid, sensitive and reliable detection of pesticide residues in vegetables can be realized using such functional SERS substrate. Scientific basis, key techniques and materials will be provided for the SERS-based rapid detection of pesticide residues in vegetables.

蔬菜中农药残留严重危害着人类健康；而传统检测技术难以对其进行快速检测。表面增强拉曼散射(SERS)技术能够快速、准确检测低浓度有机物。近年来，SERS技术检测农药残留时遇到难以同时实现高灵敏度和高可信度检测的难题。本项目拟研发SERS活性高、信号重现性好且能够捕获农药分子的SERS基底。利用有序聚苯乙烯球模板，电沉积构筑贵金属反蛋白石结构SERS基底。有序模板辅助制备法保证基底拥有较好的SERS信号重现性，确保检测结果具有高可信度。合适的表面修饰确保基底通过范德华力等作用捕获农药分子。反蛋白石结构具有密排的贵金属次级纳米结构，提供三维分布的、高密度SERS“热点”，因而其拥有高SERS活性，并对捕获的农药分子具有高SERS敏感性。利用该功能化SERS基底，实现对叶菜类蔬菜中农药残留的快速、灵敏、高可信度检测。该研究将为基于SERS效应快速检测蔬菜中农药残留提供科学依据、关键技术与核心材料。

蔬菜中农药残留严重危害着人类健康；而传统检测技术难以对其进行快速检测。表面增强拉曼散射(SERS)技术能够快速、准确检测低浓度有机物。近年来，SERS技术检测农药残留时遇到难以同时实现高灵敏度和高可信度检测的难题。本项目研发了SERS活性高、信号重现性好且能够捕获农药分子的SERS基底。利用有序聚苯乙烯球模板，电沉积构筑贵金属反蛋白石结构SERS基底。有序模板辅助制备法保证基底拥有较好的SERS信号重现性，确保检测结果具有高可信度。反蛋白石结构具有密排的贵金属次级纳米结构，提供三维分布的、高密度SERS“热点”，因而其拥有高SERS活性，并对捕获的农药分子具有高SERS敏感性。利用该功能化SERS基底，实现对叶菜类蔬菜中农药残留的快速、灵敏、高可信度检测。此外，我们设计构筑了多种具有高SERS活性和强吸附能力的二维或三维石墨烯/银纳米颗粒复合结构SERS衬底，该衬底能够集石墨烯的化学增强效应和密集的银纳米颗粒的物理增强效应为一体，因而具有更高的SERS活性；同时，该衬底能够利用石墨烯的吸附能力以及石墨烯与农药分子等有毒有机污染物分子之间的π-π相互作用实现对待测分子的靶向富集，从而实现对农药残留和持久性有机污染物的快速痕量检测。利用构筑的高性能SERS基底，实现了对农药福美双、福美铁、甲基对硫磷和噻菌灵等，以及多环芳烃芘、蒽和菲等和多氯联苯等有毒物质的快速痕量检测，达到的检测下限均低于国家标准规定的蔬菜中最大残留限量，表明该检测技术具有实际应用前景。该研究将为基于SERS效应快速检测蔬菜中农药残留提供科学依据、关键技术与核心材料。