Lee Donghoon, Lee Sangyeop, Seong Gi Hun, Choo Jaebum, Lee Eun Kyu, Gweon Dae-Gab, Lee Sanghoon
Department of Applied Chemistry, Hanyang University, Ansan 426-791, South Korea.
Appl Spectrosc. 2006 Apr;60(4):373-7. doi: 10.1366/000370206776593762.
A fast and ultra-sensitive trace analysis of methyl parathion pesticides in a polydimethylsiloxane (PDMS) microfluidic channel was investigated using confocal surface-enhanced Raman spectroscopy (SERS). A three-dimensional PDMS-based passive micromixer was fabricated for this purpose. This PDMS micromixer showed a high mixing efficiency because a strong chaotic advection was developed by the simultaneous vertical and transverse dispersion of the confluent streams. The confocal SERS signal was measured after methyl parathion pesticides were effectively adsorbed onto silver nanoparticles while flowing along the upper and lower alligator-teeth-shaped PDMS channel. A quantitative analysis of the methyl parathion pesticides was performed based on the measured peak height at 1246 cm-1. Our method has a detection limit of 0.1 ppm. This value satisfies the requirement recommended by the Collaborative International Pesticides Analytical Council (CIPAC) for the determination of methyl parathion in pesticide formulations. This study demonstrates the feasibility of using confocal SERS for the highly sensitive detection of methyl parathion pesticides in a PDMS microfluidic channel.
利用共聚焦表面增强拉曼光谱（SERS）对聚二甲基硅氧烷（PDMS）微流控通道中的甲基对硫磷农药进行了快速且超灵敏的痕量分析。为此制作了一种基于三维PDMS的被动微混合器。这种PDMS微混合器显示出高混合效率，因为合流液流的同时纵向和横向分散产生了强烈的混沌平流。在甲基对硫磷农药沿着上下鳄鱼齿形PDMS通道流动时有效吸附到银纳米颗粒上之后，测量了共聚焦SERS信号。基于在1246 cm-1处测得的峰高对甲基对硫磷农药进行了定量分析。我们的方法检测限为0.1 ppm。该值满足国际农药分析协作委员会（CIPAC）推荐的农药制剂中甲基对硫磷测定要求。本研究证明了使用共聚焦SERS在PDMS微流控通道中高灵敏检测甲基对硫磷农药的可行性。
