Self-assembled functional organic monolayers on oxide-free copper.

The preparation and characterization of self-assembled monolayers on copper with n-alkyl and functional thiols was investigated. Well-ordered monolayers were obtained, while the copper remained oxide-free. Direct attachment of N-succinimidyl mercaptoundecanoate (NHS-MUA) onto the copper surface allowed for the successful attachment of biomolecules, such as β-d-glucosamine, the tripeptide glutathione, and biotin. Notably, the copper surfaces remained oxide-free even after two reaction steps. All monolayers were characterized by static water contact angle measurements, X-ray photoelectron spectroscopy, and infrared reflection absorption spectroscopy. In addition, the biotinylated copper surfaces were employed in the immobilization of biomolecules such as streptavidin.