Incorporation of redox molecules into the monolayer modified electrodes

The electrochemical characteristics of self-assembled alkanethiol monolayer s on polycrystalline gold electrodes were studied by means of cyclic voltam metry (CV) and by measuring the monolayer transient total capacitance chang es during the CV scan. These monolayers were modified by introduction of re dox molecules either by partitioning to the monolayer moiety or by covalent coupling to the alkanethiol molecules forming the monolayer, such as to fo rm the ''gated'' access to the electrode surface for the electron transfer (redox) reaction. This paper describes three ways of introducing such "gate d" access to the electrode surface modified with long-chain n-alkanethiols, which are currently used in our laboratory. We will review some of our rec ent results, obtained for different types of redox molecules incorporated i nto the monolayer-modified electrodes. These are: redox molecules "trapped" in the monolayer moiety; redox centers chemically bound to the monolayer a t the electrode surface; and conducting polymers introduced into the monola yer at the surface of the electrode. (C) 1999 Elsevier Science S.A. All lig hts reserved.