Self-assembled monolayers of the alkanethiols having OH, COOH and NH2 terminal group were formed on a gold electrode via a sulfur attachment. The effects of their terminal groups on the redox responses of Fe(CN)3-6, Ru(NH3)3+6 and 1,1′-ferrocenedimethanol (FcDM0) aqueous solutions were investigated by cyclic voltammetry. The voltammetric response of Fe(CN)3-6 was decreased in the order of NH2 > OH > COOH terminal group. In contrast, the response of Ru(NH3)3+6 was increased in the order of NH2 < OH < COOH. In the case of FcDM0, the response was in the order of COOH > OH > NH2. These results were discussed in relations to the effect of charged terminal group on (a) the shift of the potential drop across the diffuse layer and (b) the change of the concentration of redox species at the electrode surface which is caused by the electrostatic interaction between the terminal group and ionic redox species.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)