A heated indium tin oxide (ITO) electrochemiluminescent (ECL) cell containing an ITO counter electrode, an ITO reference electrode, and a heated ITO working electrode has been fabricated to promote ionic liquid (IL)-mediated ECL reactions and hence improve sensitivities of IL-based ECL sensors. Heating the ITO working electrode was carried out by applying high-frequency ac voltages, and the temperature of the heated ITO working electrode was calibrated by the redox currents of ferrocenemethanol (FcMeOH) in 1-butyl-3-methylimidazolium hexafluorophosphate (BMIPF(6)) IL. A significant increase (26 times) in ECL intensity of the luminol-O(2)-BMIPF(6) system was observed when heating the ITO working electrode from room temperature to 54 degrees C. The use of the developed heated ITO ECL cell has been demonstrated to be an important way to improve IL-mediated ECL sensitivity and envisioned to enlarge applications of IL-based ECL sensors.