Aqueous-based initiator attachment and ATRP grafting of polymer brushes from poly(methyl methacrylate) substrates.

Many polymers, such as PMMA, are very susceptible to swelling or dissolution by organic solvents. Growing covalently attached polymer brushes from these surfaces by atom-transfer radical polymerization (ATRP) is challenging because of the typical requirement of organic solvent for initiator immobilization. We report an unprecedented, aqueous-based route to graft poly(N-isopropylacrylamide), PNIPAAm, from poly(methyl methacrylate), PMMA, surfaces by ATRP, wherein the underlying PMMA is unaffected.

Nitroavidin as a ligand for the surface capture and release of biotinylated proteins.

Discussed here is the preparation, detailed purification, and evaluation of nitroavidin as a ligand for surface capture and release of biotinylated proteins. Avidin from chicken egg white was nitrated using dilute tetranitromethane solutions. UV-vis spectroscopy was used to show decreased binding of the biotin analogue, 2-(4'-hydroxyazobenzene)benzoic acid, HABA, to nitroavidin compared to binding of HABA to native avidin.