Cu-nanoparticles were coated on the sidewall of multiwalled carbon nanotubes (MWCNTs) by a facile and effective in situ approach via the template of a polyelectrolyte (polyethylenimine or poly(sodium 4-styrene sulfonate)) noncovalently functionalized on MWCNTs. Extensive characterizations of the fabricated nanocomposites have been studied using X-ray diffraction, transmission electron microscopy, selected area electron diffraction, X-ray photoelectron spectroscopy, thermal gravimetric analysis and inductively coupled plasma. The results demonstrate that Cu-nanoparticles were well distributed on the surface of MWCNTs. The nanocomposites can be easily modified on the glassy carbon electrodes due to the presence of polyelectrolyte. The electrocatalytic activity of the modified electrodes towards glucose oxidation was investigated by cyclic voltammetry and chronoamperometry. The nanocomposites showed good non-enzymatic electrocatalytic responses to glucose in alkaline media, and can be used for the development of enzyme-free glucose sensors. (C) 2010 Elsevier Ltd. All rights reserved.