Cerium oxide (CeO(2)) nanoparticles have been self-assembled onto sol-gel derived silicon-oxide (SiO(2)) film fabricated onto indium tin oxide (ITO) coated glass plate. These SiO(2)-CeO(2) nanocomposite films have been used to immobilize the double stranded calf thymus deoxy ribose nucleic acid (dsCf-DNA) by physical adsorption to detect cypermethrin (CM). Both CeO(2)-SiO(2)/ITO electrode and dsCT-DNA/CeO(2)-SiO(2)/ITO bioelectrodes have been characterized using Fourier transform infrared (FTIR) spectroscopy, scanning electron microsopy (SEM) and differential pulse voltammetry (DPV) to confirm the formation of CeO(2)-SiO(2) nanocomposite and binding of dsCT-DNA with CeO(2)-SiO(2) nanocomposite. Electrochemical response studies of dsCT-DNA/CeO(2)-SiO(2)/ITO bioelectrode carried out as a function of CM concentration using DPV technique exhibit detection limit up to 0.0025 ppm with response time of 30 s. (C) 2010 Elsevier B.V. All rights reserved.