“…Compared to the solution‐phase Ru(bpy) 3 2+ ‐ECL system, solid‐state Ru(bpy) 3 2+ ‐ECL sensors can exhibit some merits such as an enhanced ECL signal, low consumption of expensive ECL reagent and reusable sensing applications based on Ru(bpy) 3 2+ recycled at the electrode surface 10–13. A number of approaches have been developed to fabricate solid‐state Ru(bpy) 3 2+ ‐ECL sensors, including Langmuir‐Blodgett 14, 15, sol‐gel 16, layer by layer self‐assembly 17, 18 and electrostatic interaction techniques 19. In general, to fabricate a solid‐state ECL sensor, a substrate electrode is indispensable on which Ru(bpy) 3 2+ is immobilized.…”