Carbon paste electrode modified with polyacrylonitrile nanofibers/ Ni0.5Zn0.5Fe2O4 nanocomposite as a voltammetric sensor for the determination of noscapine drug in biological samples

Measuring drugs in biological matrixes is one of the most important issues in the pharmaceutical industry. Drugs determination in the biological and human sample has many commonly used approaches such as chromatography methods. But, these approaches are often expensive, complex, time-consuming, and difficult to handle. Not surprisingly, electrochemical approaches are inexpensive and easy to operation [1, 2]. Herein, a method has been developed for the direct voltammetric determination of noscapine in biological samples utilizing polyacrylonitrile nanofibers/Ni0.5Zn0.5Fe2O4 nanocomposite as a novel modifier in carbon paste electrode (CPE). The modifier was synthesized according to a simple electrospinning method and was fully characterized using methods such as Fourier transform infrared spectroscopy, scanning electron microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. Preliminary experiments showed that the nanocomposite had an electro-catalytic effect on the electro-oxidation of noscapine and a significant improvement in the drug anodic current was obtained at +0.633 V (vs. Ag/AgCl). Therefore, the nanocomposite was utilized to modify CPE electrodes for differential pulse voltammetric determination of the investigated drug. The experimental conditions and instrumental parameters such as pH, modulation amplitude, modulation time, step potential, and scan rate were optimized. Under the optimum conditions, the calibration curve was linear in the concentration range of 2-400 µM with a detection limit of 0.8 µM. The spiked/recovery experiments showed that the developed method could be successfully applied to the determination of noscapine in biological fluids with good recoveries and minor matrix effects.