In this study, a novel sensitive and selective electrochemical sensor was developed by electropolymerization of molecularly imprinted polymer (MIP) which was synthesized onto a Au electrode in phosphate buffered saline (PBS) using cyclic voltammetry in the presence of methyl parathion (MP) as template molecules and phenol as functional monomer. In addition, a previous electrode modification was performed by deposition of a suspension of nitrogen doped graphene sheets (N-GS) on the electrode's surface. Cyclic voltammetry (CV) was employed to evaluated the molecularly imprinted and non-molecularly imprinted (nMIP) polymer in a ferric solution. The molecularly imprinted polymer exhibited a high selectivity and sensitivity toward MP. Under the optimum operating conditions, MP can be determined in the range of 0.1 to 10 mu g mL(-1) with a detection limit of 0.01 mu g mL(-1). The new molecularly imprinted sensor (MIS) is selective, sensitive, stable, simple to construct and easy to operate. The MIP sensor has been successfully applied to analysis of MP in river samples. (C) 2013 Published by Elsevier Ltd.