Incorporation of redox molecules into the monolayer modified electrodes1

The electrochemical characteristics of self-assembled alkanethiol monolayers on polycrystalline gold electrodes were studied by means of cyclic voltammetry (CV) and by measuring the monolayer transient total capacitance changes during the CV scan. These monolayers were modified by introduction of redox molecules either by partitioning to the monolayer moiety or by covalent coupling to the alkanethiol molecules forming the monolayer, such as to form the “gated” access to the electrode surface for the electron transfer (redox) reaction. This paper describes three ways of introducing such “gated” access to the electrode surface modified with long-chain n-alkanethiols, which are currently used in our laboratory. We will review some of our recent results, obtained for different types of redox molecules incorporated into the monolayer-modified electrodes. These are: redox molecules “trapped” in the monolayer moiety; redox centers chemically bound to the monolayer at the electrode surface; and conducting polymers introduced into the monolayer at the surface of the electrode.