Sensitive electrochemical sensor using polypyrrole-coated Fe3O4 core-shell nanoparticles/multiwall carbon nanotubes modified graphite electrode for atorvastatin analysis

In the present paper, the voltammetric oxidation of atorvastatin (AT) was studied at graphite electrode (GE) modified with polypyrrole-coated Fe3O4 nanohybrid by core-shell structure (Fe3O4@PPy NPs) and multiwall carbon nanotubes (MWCNTs). The modified electrode (Fe3O4@PPy/MWCNTs/GE) utilized for analysis of AT, using cyclic voltammetry (CV) and square wave voltammetric (SWV) procedures over a wide pH range. The prepared Fe3O4@PPy NPs were described by a field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), energy dispersive X-ray analysis (EDAX), Raman, X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET), Barrett-Joyner-Halenda (BJH) technique, and Fourier-transform infrared (FTIR) methods. The fabricated sensor also was characterized by SEM and electrochemical impedance spectroscopy (EIS) procedures. Some of the critical operational factors on AT determination trials, including the pH, sweep rate, accumulation potential, and time have been optimized. Under optimal conditions, the calibration curve has illustrated two linear segments in the concentration ranges of 0.0314-21.3 mu M, and 21.3-201 mu M with the limit of detection (LOD) of 0.0230 mu M. The mentioned sensor, which constructed with this method, was successfully utilized for measurements of this drug in the human blood serum samples and pharmaceutical preparations as actual samples.