An investigation of the kinetics of electron transfer across a self assembled dodecanethiol monolayer between [Fe(CN)(6)](3-/4-) and a gold electrode has been carried out using electrochemical impedance spectroscopy (EIS) at various negative dc potentials relative to the formal potential of the [Fe(CN)(6)](3-/4-) couple. Analysis of the data obtained from fitting to the Randles model shows: (a) the electron transfer coefficient x is dependent on potential; and (b) the monolayer formed by the dodecanethiol does not appear to be modified (e.g. no defects are observed) when probed by the [Fe(CN)(6)](3-/4-) couple over the potential range used in the study, which is 0 to -0.7 V versus formal potential of [Fe(CN)(6)](3-/4-).