A novel three-dimensional network of CuCr2O4/CuO nanofibers for voltammetric determination of anticancer drug methotrexate

Considering the importance of measuring anticancer drugs, a carbon paste electrode (CPE) modified with CuCr2O4/CuO nanofibers in the presence of hydrophobic ionic liquid (IL) was fabricated for methotrexate (MTX) sensing. CuCr2O4/CuO nanofibers were prepared by electrospinning method. Then, the morphology and structure of the nanofibers were studied by scanning electron microscopy, thermal analysis, X-ray diffraction, energy-dispersive X-ray, map analysis, and FT-IR spectroscopy. The electrochemical behavior of MTX at CuCr2O4/CuO/IL/CPE surface was studied using cyclic voltammetry, differential pulse voltammetry, and electrochemical impedance spectroscopy. After optimization of the experimental parameters, the prepared sensor showed a low detection limit of 25 nM MTX, based on signal-to-noise (S/N = 3), and it can determine in a wide range of 0.1-300 mu M in Britton-Robinson buffer solution at pH 2.5. The modified electrode was used to determine MTX concentration in blood and urine samples with good recoveries of 94.1-104.3. This sensor has several advantages such as low cost, easy preparation, high-performance speed and high sensitivity, selectivity, stability, and repeatability. Graphical abstract Scheme of preparation of CuCr2O4/CuO nanofibers by electrospinning method and design of a carbon past electrode using prepared nanofibers (CuCr2O4/CuO/IL/CPE). This electrode was used for methotrexate determination in plasma and urine samples using differential pulse voltammetry.