Abstract Glassy carbon (GC) electrodes coated with polystyrene (PSt) films containing surface-active agents have been studied. GC electrodes coated with PSt films containing sodium n-dodecylbenzenesulfonate (DBS) as an anionic surface-active agent bind Ru(bpy) 2+ 3 in high surface concentrations in aqueous solutions. Rotating disc electrode measurements have clarified that the incorporated Ru(bpy) 2+ 3 in the coated layer mediates the electron transfer reaction of Ru(bpy) 2+ 3 in solution at the electrodes, and the rate constant of the electron transfer is influenced by the quantity of the coated polystyrene. If lauryltrimethylammonium chloride (LMA) or laurylpyridinium chloride (LPy) as a cationic surface-active agent is blended in the coated PSt layers, the resulting electrodes bind Fe(CN) 3− 6. The electrodes coated with PSt films containing surface-active agents do not show any electrochemical reactivities for electroactive species having the same polar charges as the surface-active agents used because of electrostatic repulsions between them.