An effective electrochemiluminescence (ECL) sensor was developed by combining Ru(bpy) 2þ 3 with multiwalled carbon nanotubes(MWNTs) doped polyvinyl butyral (PVB) film. The doped film can prevent the leakage of Ru(bpy) 2þ 3 efficiently and the immobilized Ru(bpy) 2þ 3 kept its electrocatalytic activity toward the electrooxidation of tripropylamine (TPA), suggesting PVB and MWNTs were proper matrix to immobilize Ru(bpy) 2þ 3 by hydrophobic interaction. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and electrochemiluminescent characterization were employed to study the presented sensor. A wide linear dynamic range of 6 orders of magnitude between ECL intensity and concentration of TPA was found from 1 Â 10 À8 M to 5 Â 10 À2 M, with a detection limit of 3.5 Â 10 À9 M.