Electrogenerated chemiluminescence of Ru(bpy)32+ at MoS2 nanosheets modified electrode and its application in the sensitive detection of dopamine.

Electrogenerated chemiluminescence (ECL) of Ru(bpy)32+ was studied at a MoS2 nanosheets modified glassy carbon electrode (MoS2NS/GCE) in neutral condition. Electrochemical results revealed that MoS2 nanosheets could significantly catalyze the electrochemical oxidation of Ru(bpy)32+, as a result, strong anodic ECL was obtained. Several impact factors, such as the modified amount of MoS2 nanosheets suspension, the pH value, and the concentration of Ru(bpy)32+, were investigated to obtain the optimal experimental condition. Dopamine exhibited apparent inhibiting effect on ECL intensity of Ru(bpy)32+-MoS2 nanosheets through energy transfer process, and could be sensitively detected in the range of 1.0 × 10-9 to 1.0 × 10-4 mol L-1. The linear equation between the decrease of ECL intensity and the logthium of dopamine concentration was determined as ΔI = 9965.02 + 1077.03lgC (C in mol L-1), with the detection of 8.5 × 10-10 mol L-1 (3σ). The modified electrode exhibited satisfactory sensitivity, selectivity, and stability, which can be used to detect dopamine in real samples.