Electrochemical determination of atorvastatin on nano-scaled polypyrrole film

• CNTs acted as the best nano-sized substrate for electro-polymerization of pyrrole.
• PPY/CNTs/GCE displayed improved sensitivity for atorvastatin.
• Two linear dynamic ranges and a low detection limit were obtained.

Pyrrole was electro-polymerized on the surface of the glassy carbon electrode (GCE) coated with a thin film of carbon nanomaterials, including carbon nanotubes (CNTs), carbon nanoparticles (CNPs), nanodiamond-graphite (NDG) or graphite nanopowder (GNP). Morphology, thickness, stability and loading of the polypyrrole (PPY) film were significantly affected by the structure and morphology of the sub-layer of carbon nanomaterials. Electrochemical oxidation of atorvastatin (ATOR) was investigated. Under the optimized conditions, a significant increase in the peak current (compared to other modified electrodes and bare GCE) and a negative shift in the peak potential (compared to bare GCE) were observed on the surface of the CNTs/PPY modified electrode. The electrode was able to completely resolve the voltammetric response of ATOR from potentially interfering species, e.g. ascorbic acid (AA), uric acid (UA) and dopamine (DA) which are present in many biological systems. Two linear dynamic ranges of 0.005–0.1 μM and 0.1–1 μM with a detection limit of 1.5 nM and a sensitivity of 267.68 (± 1.26) μA/μM were obtained for ATOR from linear sweep voltammetry (LSV) measurements. The modified electrode with high sensitivity, stability and good reproducibility showed promising results for determination of the ATOR concentration in pharmaceutical and clinical preparations.