Walking peptide on Au(110) surface: Origin and nature of interfacial process

• Published in: Surface science 2014-10, Vol.628, p.21-29
• Main Authors: Humblot, V., Tejeda, A., Landoulsi, J., Vallée, A., Naitabdi, A., Taleb, A., Pradier, C.-M.
• Format: Article
• Language: English
• Subjects: AR-XPS; Au STM; Chemical Sciences; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Gold; Insulin growth factor (IGF); Islands; Low energy electron diffraction; Networks; Peptides; Physics; Reconstruction; Scanning tunneling microscopy; Surface chemistry; Surface reconstruction; Symmetry
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/j.susc.2014.05.004

IGF tri-peptide adsorption on Au(110)-(1×2) under Ultra High Vacuum (UHV) conditions has been investigated using surface science techniques such as synchrotron based Angle Resolved X-ray Photoemission Spectroscopy (AR-PES or AR-XPS), Low Energy Electron Diffraction (LEED) and Scanning Tunnelling Microscopy (STM). The behaviour of IGF molecules has been revealed to be coverage dependent; at low coverage, there is formation of islands presenting a chiral self-organised molecular network with a (4 2, −3 2) symmetry as shown by Low Energy Electron Diffraction (LEED) and Scanning Tunnelling Microscopy (STM) on the unaltered Au(110)-(1×2) reconstruction, suggesting significant intermolecular interactions. When the coverage is increased, the islands grow bigger, and one can observe the disappearance of the self-organised network, along with a remarkable destruction of the (1×2) substrate reconstruction, as shown by STM. The effect of IGF on the surface gold atoms has been further confirmed by angle-resolved photoemission measurements which suggest a modification of the electronic states with the (1×2) symmetry. The resulting molecular organisation, and overall the gold surface disorganisation, prove a strong surface-molecule interaction, which may be probably be explained by a covalent bonding. •IGF tripeptides was adsorbed on Au(110) under UHV conditions.•A low coverage of IGF molecules induces 2D chiral arrays as evidenced by STM data.•A high coverage of IGF molecules shows no more order in the adlayer.•A high coverage of IGF induces disorder in the top most gold atoms layer.•The gold atoms transportation is evidenced by the loss of the 2D Fermi surface.