Electrochemistry of Ferrocenoyl β-Peptide Monolayers on Gold
- 2 October 2009
- journal article
- Published by American Chemical Society (ACS) in Langmuir
- Vol. 26 (2), 1334-1339
- https://doi.org/10.1021/la902402t
Abstract
The electrochemistry of self-assembled monolayers (SAMs) on gold containing a lipoic acid linker, the β-peptide sequence (β3Val-β3Ala-β3Leu)n for n = 1, 2, and a terminal ferrocenyl group has been described for the first time. Circular dichroism (CD), NMR, and molecular modeling were used to evaluate the β-peptide structure in solution, while the monolayer film organization and electron-transfer kinetics were evaluated by cyclic voltammetry, chronoamperometry (CA), and ellipsometry. The peptides were assembled from trifluoroethanol solutions, where they are linear (n = 1) or helical (n = 2) based on CD, NMR, ellipsometry, and modeling evidence. The structure of the SAMs is less well understood. There is evidence for noncompact layers that allow electrolyte ions to approach the interface. Electron-transfer rates for n = 1, 2 were found to be 2500 and 1200 s−1, respectively, and CA evidence indicated that the transfer is based on the hopping mechanism.Keywords
This publication has 43 references indexed in Scilit:
- Helices and other secondary structures of β‐ and γ‐peptidesPeptide Science, 2005
- Electron Transfer through H-bonded Peptide AssembliesThe Journal of Physical Chemistry B, 2004
- Do Valine Side Chains Have an Influence on the Folding Behavior of β‐Substituted β‐Peptides?Helvetica Chimica Acta, 2004
- The World of β‐ and γ‐Peptides Comprised of Homologated Proteinogenic Amino Acids and Other ComponentsChemistry & Biodiversity, 2004
- How we drifted into peptide chemistry and where we have arrived atTetrahedron, 2004
- β2‐amino acids—syntheses, occurrence in natural products, and components of β‐peptides1,2Peptide Science, 2004
- Electrochemical and Surface Study of Ferrocenoyl OligopeptidesThe Journal of Physical Chemistry B, 2003
- Long-Range Electron Transfer over 4 nm Governed by an Inelastic Hopping Mechanism in Self-Assembled Monolayers of Helical PeptidesJournal of the American Chemical Society, 2003
- Long-Range Heterogeneous Electron Transfer Between Ferrocene and Gold Mediated By n-Alkane and N-Alkyl-Carboxamide BridgesThe Journal of Physical Chemistry B, 2000
- Probing the Helical Secondary Structure of Short‐Chain β‐PeptidesHelvetica Chimica Acta, 1996