Raman on a disc: high-quality Raman spectroscopy in an open channel on a centrifugal microfluidic disc.

Area of Science:

• Analytical Chemistry
• Microfluidics
• Spectroscopy

Background:

• Lab-on-a-disc technology offers potential for portable analytical devices.
• Raman spectroscopy provides molecular fingerprint information but can be challenging to implement in microfluidic systems.

Purpose of the Study:

• To demonstrate the integration of centrifugal disc microfluidics with Raman spectroscopy for melamine detection in milk.
• To achieve sensitive and reproducible detection without sample pre-processing or signal enhancement.

Main Methods:

• Utilized centrifugal disc microfluidics with uncovered channels for sample handling.
• Employed Raman spectroscopy for direct detection of melamine in liquid milk.
• Investigated the effect of centrifugal disc rotation and microchannel geometry on filling and meniscus control.

Main Results:

• Successfully detected very low concentrations of melamine in liquid milk.
• Achieved a limit of detection (LOD) of 203 ppm for melamine in milk after drying.
• Demonstrated reproducible Raman detection with quantitative precision.
• Confirmed no spectral contamination from the polymeric chip.

Conclusions:

• Centrifugal disc microfluidics provides a simple and effective platform for implementing Raman spectroscopy in lab-on-a-disc devices.
• This integrated system enables sensitive, rapid, and reproducible detection of melamine in milk without pre-processing.
• The technology holds promise for industrial applications requiring on-site analysis.