Journal of Polymer Science Part A: Polymer Chemistry, Vol.50, No.21, 4443-4450, 2012
RAFT-mediated synthesis of poly[(oligoethylene glycol) methyl ether acrylate] brushes for biological functions
The synthesis of poly[(oligoethylene glycol) methyl ether acrylate] [poly(OEGA)] brushes was achieved via reversible addition-fragmentation chain transfer (RAFT) polymerization and used to selectively immobilize streptavidin proteins. Initially, gold surfaces were modified with a trithiocarbonate-based RAFT chain transfer agent (CTA) by using an ester reaction involving a gold substrate modified with 11-mercapto-1-undecanol and bis(2-butyric acid)trithiocarbonate. poly(OEGA) brushes were then prepared via RAFT-mediated polymerization from the surface-immobilized CTA. The immobilization of CTA on the gold surface and the subsequent polymer formation were followed by ellipsometry, X-ray photoelectron spectroscopy, grazing angle-Fourier transform infrared spectroscopy, atomic force microscopy, and water contact-angle measurements. RAFT-mediated polymerization method gave CTA groups to grafted poly(OEGA) termini, which can be converted to various biofunctional groups. The terminal carboxylic acid groups of poly(OEGA) chains were functionalized with amine-functionalized biotin units to provide selective attachment points for streptavidin proteins. Fluorescence microscopy measurements confirmed the successful immobilization of streptavidin molecules on the polymer brushes. It is demonstrated that this fabrication method may be successfully applied for specific protein recognition and immobilization. (c) 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Keywords:biological applications of polymers;biotin-streptavidin;functionalization of polymers;polymer brushes;protein immobilization;reversible addition fragmentation chain transfer (RAFT);surface-mediated polymerization