Inner surface modification of poly(dimethylsiloxane) microchannel with chitin for electrophoretic analysis of proteins

• Published in: Microfluidics and nanofluidics Vol. 14; no. 6; pp. 933 - 941
• Main Authors: Sueyoshi, Kenji, Hori, Yusuke, Otsuka, Koji
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.06.2013; Springer Nature B.V
• Subjects: Adsorption; Analytical Chemistry; Biomedical Engineering and Bioengineering; Chitin; Electrophoresis; Engineering; Engineering Fluid Dynamics; Microchannels; Microfluidics; Nanostructure; Nanotechnology and Microengineering; Proteins; Research Paper; Separation; Separation techniques; Surface chemistry; Vacuum drying; Inner surface modification; Chitin; Microchip electrophoresis; Protein analysis; Poly(dimethylsiloxane) microchannel
• ISSN: 1613-4982; 1613-4990
• DOI: 10.1007/s10404-012-1100-x

Microchip electrophoresis in a poly(dimethylsiloxane) microfluidic device is one of the versatile separation techniques in a micro total analysis system, while an unstable electroosmotic flow depending on an inner surface of a microchannel and a nonspecific adsorption of biogenic compounds onto the inner surface are often problematic in microchip electrophoresis. To overcome these drawbacks, a chitin-coated poly(dimethylsiloxane) microchannel was newly developed by a relatively simple experimental procedure based on vacuum drying. The obtained chitin-coating showed high durability during 10-times experiments with a stable electroosmotic flow. It was also confirmed that the chitin-coated poly(dimethylsiloxane) microchannel provided the pH-dependent electroosmotic flow related to the dissociations of amino and silanol groups of chitin and poly(dimethylsiloxane), respectively. The nonspecific adsorption of fluorescently labeled proteins onto the inner surface of the channel was well suppressed by the coating, resulting in the sharp and symmetric peak without tailing in the microchip electrophoretic analysis of proteins. The separation of the proteins was also demonstrated in the chitin-coated microchannel, so that the resolution and reproducibility of the migration time were improved as compared to those in the untreated microchannel.