The circuit element has a first layer composed of an electrically insulating
substrate material and a first electrically conductive material which is in the
form of at least one discrete area such that it is embedded in the substrate material
and/or is applied to the substrate material. Furthermore, it has a second layer
having a second electrically conductive material, and a monomolecular layer composed
of redox-active bispyridinium molecules, which is arranged between the first layer
and the second layer. The bispyridinium molecules are immobilized on the electrically
conductive material which is in the form of at least one discrete area, and make
electrical contact with the second electrical material of the second layer. Furthermore,
electrically inert molecules are immobilized on the first layer, which molecules
form a matrix which surrounds the at least one discrete area with the monomolecular
layer composed of bispyridinium molecules.