Capillary electrochromatography of peptides on microfabricated poly(dimethylsiloxane) chips modified by cerium(IV)-catalyzed polymerization.

Vinylsulfonic acid, acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid (AMPS), 4-styrenesulfonic acid, and stearyl methacrylate were used for successful modification of the surface of poly(dimethylsiloxane) (PDMS) by cerium(IV) catalyzed polymerization on microfabricated collocated monolith support structures microchips. Reproducible and stable coatings were obtained allowing highly efficient separations of a peptide mixture with RSD for retention times below 2.6%. AMPS-coated PDMS channels were shown to give a reproducible separation of a synthetic peptide mixture for over a month. Subsequent modification of microchip channels by AMPS and methoxydimethyloctadecylsilane allowed selective separation of complex bovine serum albumin digest with high reproducibility, and efficiency of about 620,000 plates/m.