Nanoliter capillary electrochromatography columns based on collocated monolithic support structures molded in...

Area of Science:

• Analytical Chemistry
• Materials Science
• Biotechnology

Background:

• Miniaturization in analytical chemistry is a key trend.
• Developing cost-effective and disposable analytical tools is crucial for wider accessibility.
• Microfluidic devices offer potential for integrated analytical systems.

Purpose of the Study:

• To create an inexpensive, disposable liquid chromatography column on a poly(dimethyl siloxane) (PDMS) chip.
• To demonstrate a facile fabrication method for micro-scale chromatography columns.
• To evaluate the separation performance of the fabricated PDMS chip column for biological samples.

Main Methods:

• Fabrication of a PDMS chip with integrated monolithic support structures (COMOSS) using molding techniques.
• Utilizing positive photo-resist (SPR 220) to define column dimensions on a master.
• Performing separations in capillary electrochromatographic (CEC) mode.

Main Results:

• Successfully fabricated a micro-scale liquid chromatography column on a PDMS chip.
• Achieved column dimensions of 2.7-5.2 microm wide by 10.0 microm deep.
• Demonstrated effective separation of peptides from a tryptic digest of fluorescein isothiocyanate labeled bovine serum albumin (FITC-BSA).
• Obtained high column efficiencies of 4.0 x 10(5) plates/m in CEC mode.

Conclusions:

• The developed PDMS chip chromatography column is a viable, inexpensive, and disposable analytical tool.
• The fabrication method using COMOSS is efficient for creating microfluidic chromatography devices.
• The device shows promise for the analysis of complex biological samples, such as peptide mixtures.