title: Cross-linked coatings for electrophoretic separations in poly(dimethylsiloxane) microchannels.
abstract: We have developed a strategy using ultraviolet light to polymerize mixed monomer solutions onto the surface of a poly(dimethylsiloxane) (PDMS) microdevice. By including monomers with different chemical properties, electrophoretic separations were optimized for a test set of analytes. The properties of surfaces grafted with a single neutral monomer, a neutral and a negative monomer, or a neutral, negative, and cross-linking monomer were assessed. The highest quality separations were achieved in channels with cross-linked coatings. The separation efficiency for biologically relevant peptides (kinase substrates) on these surfaces was as high as 18 600 theoretical plates in a 2.5 cm channel. The test peptides were fluorescein-AEEEIYGEFEAKKKK, fluorescein-GRPRAATFAEG, fluorescein-GRPRAA(T-PO(3))FAEG, fluorescein-DLDVPIP GRFDRRVSVAAE, and fluorescein-DLDVPIPGRFDRRV(S-PO(3))VAAE. Separations between two different peptides occurred in as little as 400 ms after injection into the separation channel. The simultaneous separation of five kinase and phosphatase substrates was also demonstrated. By carefully selecting mixtures of monomers with the appropriate properties, it may be possible to tailor the surface of PDMS for a large number of different electrophoretic separations.
authors: Center for Biomedical Engineering, University of California, Irvine, CA 92697, USA.
authors: Shuwen
authors: S
authors: Hu
authors: Xueqin
authors: X
authors: Ren
authors: Mark
authors: M
authors: Bachman
authors: Christopher E
authors: CE
authors: Sims
authors: G P
authors: GP
authors: Li
authors: Nancy
authors: N
authors: Allbritton
mesh_terms: D000595:Amino Acid Sequence; D003432:Cross-Linking Reagents; D004129:Dimethylpolysiloxanes; D019075:Electrophoresis, Capillary / Q000379:methods; D005452:Fluoresceins; D008904:Miniaturization / Q000379:methods; D015336:Molecular Probe Techniques; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000302:isolation & purification; D010455:Peptides / Q000737:chemistry* / Q000302:isolation & purification; D011092:Polyethylene Glycols; D012828:Silicones
chemical_list: D003432:Cross-Linking Reagents; D004129:Dimethylpolysiloxanes; D005452:Fluoresceins; D010446:Peptide Fragments; D010455:Peptides; D012828:Silicones; D011092:Polyethylene Glycols; C013830:baysilon