Amperometric detection of tolazoline (TL) was carried out on a gold nanoparticles (AuNPs)/poly-o-aminothiophenol (PoAT)-modified electrode by a molecular imprinting technique and electropolymerization method. The modification procedure was characterized via electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The recognition between the imprinted sensor and target molecule was observed by measuring the variation of amperometric response of the oxidation-reduction probe, K3Fe(CN)(6) on electrode. Under the optimal experimental conditions, the peak currents were proportional to the concentrations of tolazoline in two ranges of 0.05-5.0 mu g mL(-1) and 5.0-240 mu g mL(-1) with the detection limit of 0.016 mu g mL(-1). Meanwhile the prepared sensor showed sensitive and selective binding sites for tolazoline. The enhancement of sensitivity was attributed to the presence of AuNPs which decreased the electron-transfer impedance. (C) 2010 Elsevier Ltd. All rights reserved.