Effect of a strong interfacial electric field on the orientation of the dipole moment of thiolated aib-oligopeptides tethered to mercury on either the N- or C-terminus

  • Becucci L
  • Guryanov I
  • Maran F
 et al. 
  • 22


    Mendeley users who have this article in their library.
  • 14


    Citations of this article.


Four oligopeptides consisting of a sequence of alpha-aminoisobutyric acid (Aib) residues, thiolated at either the N- or C-terminus by means of a -(CH(2))(2)-SH anchor, were self-assembled on mercury, which is a substrate known to impart a high fluidity to self-assembled monolayers (SAMs). The surface dipole potential of these peptide SAMs was estimated in 0.1 M KCl aqueous solution at a negatively charged electrode, where the interfacial electric field is directed toward the metal. To the best of our knowledge, this is the first estimate of the surface dipole potential of peptide SAMs in aqueous solution. The procedure adopted consisted in measuring the charge involved in the gradual expansion of a peptide-coated mercury drop and then combining the resulting information with an estimate of the charge density experienced by diffuse layer ions. The dipole moment of the tethered thiolated peptides was found to be directed toward the metal, independent of whether they were thiolated at the C- or N-terminus. This result was confirmed by the effect of these SAMs on the kinetics and thermodynamics of the Eu(III)/Eu(II) redox couple. The combined outcome of these studies indicates that a strong interfacial electric field orients the dipole moment of peptide SAMs tethered to mercury, even against their "natural" dipole moment.

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Get full text


  • Lucia Becucci

  • Ivan Guryanov

  • Flavio Maran

  • Rolando Guidelli

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free