A new nanocomposite imprinted electrochemical sensor was developed for sensitive and selectivedetermination of acetylsalicylic acid (ASA), based on a gold electrode modified with one-step elec-tropolymerization of the molecularly imprinted polymer (MIP) composed from polypyrrole (ppy), sol-gel,Silica@Gold core-Shell nanoparticles (SiO2@AuNPs) and acetylsalicylic acid. SiO2@AuNPs were intro-duced into the polymer matrix for the enhancement of electrical response of [Fe(CN)6]3−/[Fe(CN)6]4−redox pair which was used as an electrochemical active probe. The SiO2@AuNPs, were synthesized chem-ically by using a modified Stober method and they were characterized by UV–Vis spectrophotometry,Fourier transform infrared (FT-IR) spectrometry, X-ray diffraction (XRD), scanning electron microscopy(SEM) and transmission electron microscopy (TEM). Under the optimized experimental conditions, twolinear concentration ranges from 1.0 to 10.0 nM and 10.0–100.0 nM with a limit of detection (LOD) of0.2 nM was obtained. The effects of interfering species on the determination of ASA were investigatedand it was found that the proposed sensor has a high recognition capacity towards the ASA in the pres-ence of interfering species in solutions. Moreover, the reproducibility, repeatability and stability of theimprinted sensor were all found to be satisfactory. Finally, the modified electrode was successfully appliedfor determination of ASA in tablet and urine samples.

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