ELECTROCHEMICAL BEHAVIORS OF FERROCENE DERIVATIVES AT AN ELECTRODE MODIFIED WITH TERMINALLY SUBSTITUTED ALKANETHIOL MONOLAYER ASSEMBLIES

Self-assembled monolayers of 11-mercapto-1-undecanol (MUO), 11-mercapt oundecanoic acid (MUA), and 11-amino-1-undecanethiol (AUT) were formed on a gold disk electrode. The effects of the terminal charges of thes e monolayers on the redox responses of 1,1'-ferrocenedimethanol (FcDM) , (ferrocenylmethyl)trimethylammoniun bromide (FcMA) and ammonium ferr ocenesulfonate (FcSA) were evaluated by using voltammetric (CV) techni ques. The CV responses of FcDM and FcMA decreased in the order of MUA/ Au (MUA modified gold electrode), MUO/Au, and AUT/Au. In contrast, the CV response of FcSA increased in the order of MUA/Au, MUO/Au, and AUT /Au. From these results, the effects of the terminal charges on the CV responses were measured in relation to the diffuse layer potential an d the electrostatic interaction between the terminal unit and redox sp ecies.