title: Cationic starch derivatives as dynamic coating additives for analysis of amino acids and peptides using poly(methyl methacrylate) microfluidic devices.
abstract: Plastic microchips are very promising analytical devices because they are less fragile and are suitable for mass production. However, due to their hydrophobicity, the surface strongly interacts with nonpolar analytes or species containing hydrophobic domains, resulting in significant uncontrolled adsorption on channel walls. This paper describes the poly(methyl methacrylate) surface treatment by dynamic coating additives that considerably decreases adsorption of analytes to channel walls. Among the additives studied, quaternary ammonium starch derivatives suppressed the adsorption of fluorescently labeled amino acids and peptides most effectively. The effect was valid over the wide pH range from 2.5 to 8.0. Using a 10 mM phosphate buffer (pH 7.0) with 3% (w/v) quaternary ammonium starch as the running buffer, Asp and Glu, respectively, migrated at 54.6 and 57.6 s with efficiencies of 380 000 and 370 000 plates/m. In addition, this cationic starch derivative was found to possess good solubility and low viscosity.
authors.affiliation: Department of Analytical Chemistry, School of Pharmaceutical Sciences and COE Program in the 21st Century, University of Shizuoka, 52-1 Yada Shizuoka, Shizuoka, 422-8526, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Kato
authors.forename: Yukari
authors.initials: Y
authors.lastname: Gyoten
authors.forename: Kumiko
authors.initials: K
authors.lastname: Sakai-Kato
authors.forename: Tohru
authors.initials: T
authors.lastname: Nakajima
authors.forename: Toshimasa
authors.initials: T
authors.lastname: Toyo'oka
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D002240:Carbohydrate Sequence; D002412:Cations / Q000737:chemistry*; D044085:Microfluidics / Q000295:instrumentation*; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry*; D019904:Polymethyl Methacrylate / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D002412:Cations; D010455:Peptides; D019904:Polymethyl Methacrylate