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

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Microfluidics

Background:

• Malachite green (MG) is a synthetic dye with applications in aquaculture and textiles.
• Accurate and sensitive detection of MG is crucial for environmental monitoring and food safety.
• Existing trace analysis methods can be time-consuming or require complex instrumentation.

Purpose of the Study:

• To develop a rapid and highly sensitive trace analysis technique for malachite green (MG).
• To investigate the use of a polydimethylsiloxane (PDMS) microfluidic sensor combined with surface-enhanced Raman spectroscopy (SERS) for MG detection.

Main Methods:

• Fabrication of a zigzag-shaped PDMS microfluidic channel for efficient analyte-colloid mixing.
• Utilizing aggregated silver colloids as SERS substrates within the microfluidic channel.
• Optimizing flow velocity for effective adsorption of MG onto silver nanoparticles.
• Quantitative analysis of MG based on SERS peak height at 1615 cm(-1).

Main Results:

• The SERS microfluidic sensor demonstrated effective adsorption of MG molecules.
• A low limit of detection (LOD) below 1-2 ppb was achieved for MG.
• The LOD is comparable to that of liquid chromatography-mass spectrometry (LC-Mass) detection.

Conclusions:

• A new conceptual detection technology using a SERS microfluidic sensor has been introduced.
• This technology enables highly sensitive trace analysis of MG in water samples.
• The developed method offers a rapid and sensitive alternative for MG detection.