Fast and sensitive trace analysis of malachite green using a surface-enhanced Raman microfluidic sensor

• Published in: Analytica chimica acta 2007-05, Vol.590 (2), p.139-144
• Main Authors: Lee, Sangyeop, Choi, Junghyun, Chen, Lingxin, Park, Byungchoon, Kyong, Jin Burm, Seong, Gi Hun, Choo, Jaebum, Lee, Yeonjung, Shin, Kyung-Hoon, Lee, Eun Kyu, Joo, Sang-Woo, Lee, Kyeong-Hee
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Chemistry; Chromatographic methods and physical methods associated with chromatography; Exact sciences and technology; General, instrumentation; Lab on a chip; Malachite green; Microfluidic Analytical Techniques - methods; Microfluidic sensor; Other chromatographic methods; Rosaniline Dyes - analysis; Spectrometric and optical methods; Spectrum Analysis, Raman - methods; Surface-enhanced Raman spectroscopy; Trace analysis
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2007.03.049

A rapid and highly sensitive trace analysis technique for determining malachite green (MG) in a polydimethylsiloxane (PDMS) microfluidic sensor was investigated using surface-enhanced Raman spectroscopy (SERS). A zigzag-shaped PDMS microfluidic channel was fabricated for efficient mixing between MG analytes and aggregated silver colloids. Under the optimal condition of flow velocity, MG molecules were effectively adsorbed onto silver nanoparticles while flowing along the upper and lower zigzag-shaped PDMS channel. A quantitative analysis of MG was performed based on the measured peak height at 1615 cm −1 in its SERS spectrum. The limit of detection, using the SERS microfluidic sensor, was found to be below the 1–2 ppb level and this low detection limit is comparable to the result of the LC-Mass detection method. In the present study, we introduce a new conceptual detection technology, using a SERS microfluidic sensor, for the highly sensitive trace analysis of MG in water.