Ultra-micro amperometric sensor of isoniazid using carbon doped vanadium trioxide @ Prussian blue supported on graphite felt

Abstract

A sensitive and selective amperometric determination method for isoniazid (INZ), an anti-tuberculosis drug, was studied by cyclic voltammetry and chronoamperometry, using carbon doped vanadium trioxide @ Prussian blue modified graphite felt electrodes (V2O3-C@PB/GF). V2O3-C was synthesized by a solvothermal technique and fixed on GF; then PB was generated on the so-obtained V2O3-C/GF. The morphology and structure of the composite electrode were characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy and ultraviolet-visible (UV–vis) spectroscopy. After optimization of the parameters influencing the formation of V2O3-C@PB/GF, the composite electrode showed efficient electrocatalytic performance for isoniazid detection in 0.5 M potassium chloride (KCl) solution. A wide linear concentration range (2.5 ×10-9–1.1 ×10-3 M), a good sensitivity (1.378 A/M, 0.561 A/M) and a low detection limit (0.83 nM) were obtained. Furthermore, long-term stability and fabrication reproducibility of the electrochemical device have been investigated, as well as its robustness to interferent species. Finally, the practical applicability of the proposed sensor was assessed by detecting INZ in commercial tablets, bovine serum albumin and human urine samples: recovery values varied from 96.8% to 105.2%, indicating an excellent analytical performance for INZ qualification.