title: Tunable thick polymer coatings for on-chip electrophoretic protein and peptide separation.
abstract: We report a variety of procedures for fabricating confinement-induced polymer coatings, used to eliminate non-specific protein adsorption and to control electroosmotic flow for microchip capillary electrophoresis. The coating strategy generates relatively thick polymer wall coatings (100-700 nm) and can easily be tuned by adjusting the monomer concentration. 2-hydroxyethyl methacrylate (HEMA) polymer coating, photopatterned in microfluidic channels, effectively reduced protein non-specific adsorption and rendered high efficiency (N/m=∼3 × 10⁶) for protein separation. The coating strategy provides rapid and effective means to create robust wall coatings, with the ability to photograft various surface chemistries onto the coating. [2-(methacryloyloxy) ethyl] trimethylammonium chloride grafted HEMA coated channels showed high durability and reproducibility for generating EOF (RSD=2.6%, n=64) over a period of 15 days. Sulfobetaine methacrylate grafted HEMA coated channels allowed separation of BSA digest, 15 peaks resolved in 25s, with an average N/m of 4 × 10⁵.
authors.affiliation: Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2 Canada.
authors.forename: Mei
authors.initials: M
authors.lastname: He
authors.forename: Yong
authors.initials: Y
authors.lastname: Zeng
authors.forename: Abebaw B
authors.initials: AB
authors.lastname: Jemere
authors.forename: D
authors.initials: D
authors.lastname: Jed Harrison
mesh_terms: D000818:Animals; D002417:Cattle; D053841:Electroosmosis; D046209:Electrophoresis, Microchip / Q000295:instrumentation* / Q000379:methods; D008689:Methacrylates / Q000737:chemistry; D010446:Peptide Fragments / Q000032:analysis / Q000302:isolation & purification*; D011108:Polymers / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000302:isolation & purification
chemical_list: D008689:Methacrylates; D010446:Peptide Fragments; D011108:Polymers; C521589:sulfobetaine methacrylate polymer; D012710:Serum Albumin, Bovine; C005044:hydroxyethyl methacrylate