Conducting polymers have been studied extensively due to their intriguing electronic and redox properties. To improve and extend their functions, the fabrication of multi-functionalized conducting polymer nanocomposites has attracted a great deal of attention. Herein, for the first time, a simple one-step electrodeposition method was developed for the synthesis of poly(3,4-ethylene-dioxythiophene)/Zirconia nanoparticles (PEDOT/ZrO(2)NPs) composite film on a glassy carbon electrode (GCE). Data from scanning electron microscopy, energy dispersive spectrum, FTIR and UV/vis spectra, and various electrochemical techniques demonstrated that PEDOT/ZrO(2)NPs nanocomposite was successfully synthesized. The obtained PEDOT/ZrO(2)NPs nanocomposite film showed large specific area, high conductivity, rapid redox properties and had encapsulated structures, which make it an excellent sensing platform for sensitive determination of vitamin B-2 (VB2), vitamin B-6 (VB6) and vitamin C (VC). Electrochemical results obviously reveal that the catalytic peak currents of vitamins obtained at PEDOT/ZrO(2)NPs/GCE are much higher than those at PEDOT/GCE, ZrO(2)NPs/GCE and bare GCE. Using differential pulse voltammetry, detection limits of 0.012 mu M, 0.20 mu M and 0.45 mu M were obtained for VB2, VB6 and VC, respectively at PEDOT/ZrO(2)NPs/GCE. Furthermore, the modified electrode exhibited good reproducibility and long-term stability, as well as high selectivity. The facile and easy electrochemical approach used for the preparation of PEDOT/ZrO(2)NPs nanocomposite may open up new horizons in developing of cost effective electrochemical sensors. Crown Copyright (C) 2014 Published by Elsevier B.V. All rights reserved.