A novel nano-sized copper oxide/multi-wall carbon nanotubes/Nafion (CuO/MWNTs/Nafion) composite film-modified electrode was fabricated, and applied for a sensitive and selective determination of dopamine. The morphology and structure of the as-prepared CuO/MWNTs nanocomposite were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive spectrometer (EDS). The excellent electrocatalytic activity of the CuO/MWNTs/Nafion nanocomposite for the oxidation of dopamine was studied by voltammetry. Dopamine can effectively accumulate at CuO/MWNTs/Nafion composite film-modified electrode and produce a pair of sensitive redox peaks in 0.1 mol L-1 phosphate buffer solution (PBS) (pH 6.0). This newly exploited electrochemical sensor was successfully used to determine dopamine in real sample. (C) 2013 Elsevier B.V. All rights reserved.