Journal of Electroanalytical Chemistry, Vol.754, 75-79, 2015
The effect of supporting electrolyte on the electron transfer at mixed self-assembled monolayers containing ferrocene moieties
The effect of supporting electrolyte on the apparent redox potential (E-app(center dot)) of ferrocene (Fc) moieties in mixed self-assembled monolayers (SAMs) has been studied by means of cyclic and ac voltammetry. When the Fc moieties are exposed on the surface of the SAM (i.e., for the mixed SAM of Fc(CH2)(6)SH and 1-hexylmercaptan), the E-app(center dot) is little dependent on the supporting electrolytes used, i.e., sodium salts of 4-hydroxybenzenesulfonate (HBS), p-toluenesulfonate (TS), and 2-naphtalenesulfonate (NS). On the other hand, when the Fc moieties are buried in the SAM (i.e., for the mixed SAM of Fc(CH2)(6)SH and 1-octadecylmercaptan), the E-app(center dot) is significantly shifted to more positive potentials and is further affected by the nature of the electrolyte anions. The more hydrophobic the anion becomes in the order HBS