The original aim of this project was to investigate how the electrochemical activity of polymer modified electrodes depends on the polymer morphology and the structure of the polymer-electrode interface. In principle, the use of these mediating layers on electrode surfaces make it possible to control the properties of the interface at a molecular level. Firstly, the methods of data acquisition and analysis used to extract fundamental parameters of the redox polymer concerning charge transfer charactenstics have been put under PC control. This facilitates a more systematic approach to the data acquisition and analysis as compared to the methods used before. Secondly, surface science techniques have been used in an attempt to determine the chemical composition and physical structure of the polymer layer and to establish whether the surface composition was dependent on the electrochemical treatment of the polymer modified electrode. During the progress of this project, the expertise gained during the first instrumentation onented stage has been extended towards capacitance measurements on solid state systems.