Digital microfluidic sampler for a portable capillary electropherograph

Area of Science:

• Analytical Chemistry
• Microfluidics
• Separation Science

Background:

• Capillary electrophoresis (CE) is a powerful separation technique.
• Digital microfluidic (DMF) devices offer precise liquid handling.
• Integrating DMF with CE can enhance sample introduction and analysis.

Purpose of the Study:

• To develop a novel sample introduction and analysis system.
• To combine a digital microfluidic (DMF) device with a portable capillary electrophoresis (CE) analyzer.
• To demonstrate the system's capability for sample separation and concentration.

Main Methods:

• A digital microfluidic (DMF) device was coupled with a portable capillary electrophoresis (CE) analyzer.
• Sample and buffer droplets were actuated using electrowetting on dielectric (EWOD).
• Contactless conductivity detection was employed with a short separation capillary.

Main Results:

• The integrated DMF-CE system successfully separated a mixture of vitamins.
• Droplet evaporation was utilized for simultaneous sample concentration.
• The observed concentration process aligned with theoretical predictions.

Conclusions:

• The developed DMF-CE system provides an effective approach for sample introduction and analysis.
• The system demonstrates potential for portable and automated analytical applications.
• The integration facilitates efficient separation and concentration of analytes.