Quantitative Analysis of Methyl Parathion Pesticides in a Polydimethylsiloxane Microfluidic Channel Using Confocal Surface-Enhanced Raman Spectroscopy

Abstract

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.

Shell‐Isolated Nanoparticle‐Enhanced Raman Spectroscopy (SHINERS)

“…leaves contaminated by parathion and fenthion pesticides, respectively. Curve f clearly shows that we can detect characteristic bands of the two pesticides simultaneously (1107 and 1327 cm −1 for parathion [85], 1052 and 1220 cm −1 for fenthion [86]). These preliminary results demonstrate the tremendous scope of SHINERS as a field-portable and cost-effective method of analysis for industrial and daily inspection applications.…”

“…Figure 8.14a shows that normal Raman spectra recorded on a fresh orange with clean pericarps (curve a) or contaminated by parathion (curve b) only show two bands at about 1165 and 1526 cm −1 , attributed to carotenoid molecules contained in citrus fruits [84]. SHINs were then applied and two additional peaks at around 1109 and 1340 cm −1 (curve c), attributed to the characteristic bands of parathion residues [85], were clearly detected. The same result can also be obtained by using a confocal Raman spectrometer.…”

Recent advances in surface‐enhanced Raman scattering detection technology for microfluidic chips

“…The LOD for methyl parathion pesticides in vegetables, as recommended by the Collaborative International Pesticides Analytical Council (CIPAC), ranges from 0.1 to 1.0 ppm. Lee et al [93] also used the confocal SERS technique for the fast and sensitive trace analysis of methyl parathion pesticides. In this work, an LOD of 0.1 ppm was obtained, which satisfies the requirement recommended by CIPAC.…”

Rapid DNA Hybridization Analysis Using a PDMS Microfluidic Sensor and a Molecular Beacon

“…18,19 A microfluidic channel was fabricated by stacking two PDMS layers that had upper and lower teeth patterns. These layers were produced by the pattern replication of mould masters.…”