Electrophoretic separations of neuromediators on microfluidic devices

Area of Science:

• Analytical Chemistry
• Microfluidics
• Biochemistry

Background:

• Neuromediator analysis is crucial for understanding neurological functions.
• Traditional methods often require large sample volumes and complex procedures.
• Microfluidic devices offer potential for miniaturized and rapid analyses.

Purpose of the Study:

• To demonstrate on-chip capillary electrophoresis for neuromediator separation.
• To investigate factors influencing microfluidic electrokinetic characteristics and separation performance.
• To evaluate the necessity of on-chip sample stacking for neuropeptide separation.

Main Methods:

• Investigated effects of buffer composition, pH, SDS, and surface treatments on PDMS-PDMS and hybrid PDMS-glass devices.
• Employed on-chip electrokinetic sample stacking, specifically field-amplified sample stacking.
• Utilized capillary electrophoresis coupled with microfluidics for separating fluorescently labeled analytes.

Main Results:

• On-chip sample stacking was found necessary for effective neuropeptide separation on elastomer-based devices.
• Field-amplified sample stacking enabled electroosmotic flow-supported separations without specialized injection schemes.
• Separations were achieved in seconds with small injection volumes (approx. 110 pL) and high plate numbers (up to ~22,000).

Conclusions:

• On-chip capillary electrophoresis, particularly with hybrid PDMS-glass devices, is a viable method for neuromediator analysis.
• The developed method allows for rapid separation and high-efficiency analysis of neuropeptides.
• This approach holds promise for the analysis of (neuro)peptides in minute sample volumes.