New Electrochemical Sensor Based on Electrospun Carbon Nanofibers Modified with Cobalt Nanoparticles and Its Application for Atorvastatin Determination

Abstract

The presented work reports the application of the electrospun carbon nanofibers decorated with cobalt nanoparticles (CNF-Co) in the fabrication of a new, highly sensitive electrochemical sensor (GCE-CNF-Co). Morphology, phase composition and structure as well as the chemical state of the surface of used material were evaluated using the following methods: scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy and X-ray Photoelectron Spectroscopy (XPS). The proposed sensor might be characterized by a simple and fast process of preparation and low cost but in the same time exhibits excellent electrical conductivity and electrocatalytic properties. Reproducibility of its preparation expressed as relative standard deviation (%RSD) was estimated to be 9.0% (n = 5 electrodes). A single sensor might perform at least 700 measurements without compromising metrological parameters. The developed sensor was used in the determination of atorvastatin (ATOR)—substance used for the prevention of cardiovascular incidents. ATOR exhibits linear response in the range 0.08–1.04 μM (r = 0.998) and 1.2–9.1 μM (r = 0.999). Limit of detection (LOD) was equal to 3.4 nM (1.9 μg l−1) (tacc = 50 s). The applicability of the method was proved by analysis of urine and pharmaceutical products containing ATOR. Recoveries were in the range 102%–110%, what proves the accuracy of the method.