A novel nanostructured assembly based on poly(glutamic) acid/cysteine/gold nanoparticles was designed to modify the surface of a glassy carbon electrode (GCE) and used to study the atenolol oxidation. The GCE surface was initially covered by poly(glutamic) acid/cysteine layers followed by covalent attachment of citrate-capped 40 nm-AuNPs. The system excellent electrochemical performance was tested by Linear Sweep Voltammetry and Electrochemical Impedance Spectroscopy and allowed the detection of an atenolol oxidation peak (around +0.65 V/SCE) with a detection limit of 3.9 x 10 (7) M. Such findings could be incorporated in highly sensitive detection technologies of various biological or chemical compounds and molecules. (C) 2011 Elsevier B. V. All rights reserved.