Nanostructured graphene oxide–MWCNTs incorporated poly(3,4-ethylenedioxythiophene) with a high surface area for sensitive determination of diethylstilbestrol

•The nanostructured GO–MWCNTs were successfully incorporated into PEDOT matrix.•The nanocomposites can be effectively used for the detection of DES.•Low detection limit with wide linear range could be obtained.•The method was applied to determine DES in real samples. In this paper, MWCNTs functionalized with graphene oxide (GO) were incorporated into poly(3,4-ethylenedioxythiophene) (PEDOT) matrix for the synthesis of high quality PEDOT/GO functional MWCNTs (PEDOT/GO–MWCNTs) nanocomposite by using one-step electropolymerization method. The obtained nanocomposite was characterized by scanning electron microscopy (SEM), ultraviolet–visible (UV–vis) spectroscopy and Fourier transform infrared (FT-IR) spectroscopy. Then the catalytic behavior of PEDOT/GO–MWCNTs nanocomposite modified glassy carbon (GC) electrode toward diethylstilbestrol (DES) has been investigated by electrochemical techniques. Electrochemical results revealed that the oxidation peak currents of DES obtained at the PEDOT/GO–MWCNTs/GC electrode are much higher than those at the PEDOT/GC, PEDOT/GO/GC, GO–MWCNTs/GC and bare GC electrodes, which might be ascribed to the large surface area and good conductivity of PEDOT/GO–MWCNTs nanocomposite. Under optimized conditions, the anodic peak current was linear to the concentration of DES in the range from 0.01 to 20μM with the detection limit of 0.003μM. To further validate its possible application, the proposed method was successfully used for the determination of DES in pharmaceutical formulations with satisfactory results. The excellent electrocatalytic behavior of PEDOT/GO–MWCNTs may lead to new applications in electrochemical analysis.