VOLTAMMETRIC PROBING OF MULTICOMPONENT LANGMUIR-BLODGETT MONOLAYERS .1. MONOLAYERS CONTAINING UBIQUINONE (Q10)

Langmuir-Blodgett technique has been employed to prepare well-defined, multicomponent monolayers on the water-air interface and to transfer them onto the Au electrode surface. The monolayer contains ubiquinone as the electroactive component and 1 - Octadecanethiol/1 - Octadecanol mixture as the component blocking the electrode surface. The layer ex hibits high stability both in air and in the supporting electrolyte so lution. The voltammetric signal of ubiquinone assembled in the alkyl m onolayer is pH dependent. In alkaline solution almost a perfectly reve rsible electrode process is observed at low scan rates. The Laviron tr eatment of electron transfer of surface immobilized species is used to analyse the voltammograms of ubiquinone in the hydrophobic monolayer on gold. The electron transfer rate constant from the electrode to the redox unit, k(o)', and the interaction parameters between the molecul es in the monolayer are determined by following the changes of the vol tammetric peaks as a function of potential sweep rate.