Acupuncture Injection Combined with Electrokinetic Injection for Polydimethylsiloxane Microfluidic Devices

Area of Science:

• Analytical Chemistry
• Microfluidics
• Separation Science

Background:

• Acupuncture injection into polydimethylsiloxane (PDMS) microchannels allows nL-scale sample injection for microchip capillary electrophoresis.
• Previous methods faced challenges in achieving reproducible pL-scale sample injections.

Purpose of the Study:

• To develop a technique for reproducible pL-scale sample injection in microchip capillary electrophoresis.
• To combine acupuncture injection with electrokinetic injection for enhanced precision.

Main Methods:

• Developed the acupuncture injection combined with electrokinetic injection (AICEI) technique.
• Utilized PDMS microchannels for microchip capillary electrophoresis.
• Performed capillary zone electrophoresis (CZE) separation of FITC and fluorescein.

Main Results:

• Achieved reproducible pL-scale sample injections using the AICEI technique.
• Demonstrated complete separation of a mixture of FITC and fluorescein (10 µM each).
• Validated the AICEI method's effectiveness in microchip capillary electrophoresis.

Conclusions:

• The AICEI technique successfully enables precise pL-scale sample injection for microchip capillary electrophoresis.
• This method overcomes limitations of previous techniques, offering improved reproducibility.
• AICEI is effective for sensitive separation of fluorescent analytes like FITC and fluorescein.