Abstract
Electrochemiluminescence (ECL) of [Ru(bpy)3]2+ using lidocaine as coreactant has been studied upon ultrasound irradiation. ECL signal is detected at +1.2 V (vs. Ag/AgCl) at pH 9.0, which is confirmed by the generation excite state of [Ru(bpy)3]2+ through homogeneous electron transfer process between [Ru(bpy)3]3+ and lidocaine oxidative intermediate radicals at the electrode surface. At pH 11.0, however, two of specific ECL peaks are exhibited at +1.2 V and +1.5 V, respectively, indicating the different reaction route for ECL generation. Under the irradiation by 430 kHz ultrasound, the ECL intensity at +1.2 V increased with the decreasing of ECL intensity at +1.5 V. The ECL at +1.5 V is supposed to be generated between [Ru(bpy)3]3+ and the intermediate species from the electrochemical decomposition of lidocaine. Because relatively low ECL intensity at +1.5 V was measured under ultrasound irradiation, the generation of intermediate radical of lidocaine by chemical reaction to hydroxyl radical was proposed.
