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Updated: Jul 11, 2026
Synthesis, Assembly, and Characterization of Monolayer Protected Gold Nanoparticle Films for Protein Monolayer Electrochemistry
Published on: October 4, 2011
Oriented purple membrane monolayers covalently attached to gold by multiple thiole linkages analyzed by single
Michael Schranz1, Frank Noll, Norbert Hampp
1Faculty of Chemistry and Materials Sciences Center, University of Marburg, Hans-Meerwein-Strasse, D-35032 Marburg, Germany.
Abstract:
Highly oriented monolayers of bacteriorhodopsin (BR) in purple membrane (PM) form are obtained by the reaction of BR-Q3C, where a cysteine was introduced into the N-terminal region, with a gold surface. Single molecule force spectroscopy was used to show that about 50% of the BRs are covalently bound to the surface. The linkage between the cysteine and the gold causes an additional characteristic peak in the force-distance curves to appear. Because several thousand cysteine-gold bonds exist between each PM patch and the surface, the PM is irreversibly bound. Such oriented PM monolayers may serve as an interface between metal surfaces and biomaterials, which may be linked to the PM surface chemically. Photoelectric applications of BR will benefit from the high degree of orientation obtained by this method.
