A new label-free electrochemical aptasensor was constructed for sensitive and selective determina-tion of bisphenol A (BPA) based on functionalized multiwall carbon nanotubes/gold nanoparticles(f-MWCNTs/AuNPs) nanocomposite film modified gold electrode. The f-MWCNTs/AuNPs nanocompos-ite was synthesized chemically and the structure of the prepared nanocomposite was characterizedby UV–Vis spectrophotometry, Fourier transform infrared (FT-IR) spectrometry, X-ray diffraction (XRD)and transmission electron microscopy (TEM). The fabrication process of the electrochemical sensor wasalso investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in thepresence of [Fe(CN)6]3−/[Fe(CN)6]4−as an electrochemical active probe. The molecular dynamic (MD)simulations were used to study the interaction between BPA and its aptamer molecules. The effect ofseveral parameters influencing the performance of the aptasensor was investigated and they were opti-mized. Under the optimized experimental conditions, the square wave voltammetry (SWV) was appliedas a sensitive analytical method for determination of BPA in solutions and a good linear relationship wasobserved between the BPA concentration and the peak current within the range of 0.1–10 nM with adetection limit of 0.05 nM. The effect of interfering species on the determination of BPA was investigatedand it was found that the proposed aptasensor is highly selective to BPA. Also, the reproducibility andstability of the sensor were all found to be satisfactory. Finally, the developed aptasensor was successfullyapplied for determination of BPA in real samples such as mineral water, orange juice and milk.

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