Hydrogen-bonding, self-assembled monolayers: Ordered molecular films for study of through-peptide electron transfer

New peptide-containing alkanethiol self-assembled monolayers (SAMs) on gold have been prepared. These monolayers exhibit extended interchain hydrogen bonding and have well-ordered alkane chains. Elemental composition and thickness of the monolayer are obtained by X-ray photoelectron spectroscopy. External reflective IR spectroscopy shows that the SAMs are uniaxial and possess microcrystalline, densely packed methylene chains with hydrogen bonding between neighboring amide moieties. These highly ordered monolayers form excellent electrochemical spacers as characterized by electrochemical blocking studies and double-layer capacitance measurements. The well-defined structure makes this system a promising prototype for systematic investigations of long-range electron transfer through amide bonds.