Li Ruili, Chen Miao, Yang Hua, Hao Naiying, Liu Qi, Peng Mei, Wang Lumin, Hu Yuyang, Chen Xiaoqing
College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China.
School of Life Sciences, Central South University, Changsha 410013, China.
Anal Chem. 2021 Mar 16;93(10):4657-4665. doi: 10.1021/acs.analchem.1c00234. Epub 2021 Mar 2.
Rapid component separation and reliable surface-enhanced Raman scattering (SERS) detection of organochlorine pesticide (OCP) residues in real water samples remain major challenges because of sample complexity, trace content, and low molecular affinity for a metal surface. Here, we report a novel strategy of simultaneous extraction and fabrication of plasmonic colloidal gold superparticles (AuSPs) to perform rapid SERS detection of OCPs in environmental water. In this protocol, multiple components of OCPs in complex water were facilely diffused into dichloromethane (DCM) microdroplets and specifically bound to octadecylamine-modified gold nanoparticles (Au-ODAs), affording the SERS substrate through self-assembly of the OCP-trapped Au-ODA into AuSPs with the evaporation of DCM. SERS signals of the specifically prepared Au-ODA could be used as an internal standard to calibrate the absolute signal of OCPs, and multiplex detection could be achieved depending on their molecularly narrow Raman peaks. As for simultaneously sensing four kinds of OCPs (4,4'-DDT, α-endosulfan, tetradifon, and chlordane) in water, the established method showed strong anti-interference ability and comparable quantification ranges with a low limit of detection (LOD). The recoveries ranged from 90.20 to 109.4% for OCPs in farmland, river, and fishpond water, indicating that the established AuSP-based platform is reliable and applicable to the detection of OCPs in real water samples.
由于样品的复杂性、痕量含量以及对金属表面的低分子亲和力，快速分离实际水样中的有机氯农药（OCP）残留成分并进行可靠的表面增强拉曼散射（SERS）检测仍然是重大挑战。在此，我们报告了一种同时提取和制备等离子体胶体金超粒子（AuSPs）的新策略，用于对环境水中的OCPs进行快速SERS检测。在该方案中，复杂水样中OCPs的多种成分很容易扩散到二氯甲烷（DCM）微滴中，并特异性地结合到十八烷基胺修饰的金纳米粒子（Au-ODAs）上，随着DCM的蒸发，捕获了OCP的Au-ODA通过自组装形成AuSPs，从而得到SERS基底。特异性制备的Au-ODA的SERS信号可作为内标来校准OCPs的绝对信号，并且根据它们分子窄的拉曼峰可以实现多重检测。对于同时检测水中的四种OCPs（4,4'-滴滴涕、α-硫丹、三氯杀螨砜和氯丹），所建立的方法显示出很强的抗干扰能力，并且具有与低检测限（LOD）相当的定量范围。农田水、河水和鱼塘水中OCPs的回收率在90.20%至109.4%之间，这表明所建立的基于AuSP的平台可靠且适用于实际水样中OCPs的检测。
