A novel ionic liquid based electrochemical sensor for detection of pyrazinamide

Abstract

In this work, we report electrochemical detection of pyrazinamide at the surface of a glassy carbon electrode fabricated with a sensing nanocomposite comprising silver nanoparticles, 1-ethyl-3-methylimidazolium tetrafluoroborate ([Emim][BF4]) ionic liquid, and reduced graphene oxide. The electrochemical reaction of the pyrazinamide at the fabricated electrode was measured using cyclic and differential pulse voltammetric methods. Ionic liquid-reduced graphene oxide-silver nanoparticles were successfully synthesized and characterized by transmission electron microscope and Fourier transform infrared spectroscopy, respectively. The synthesized silver nanoparticles were spherical in shape with an average size of ~ 30 nm. The fabricated electrode exhibits excellent electrocatalytic utility with favourable electrochemical parameters for the reduction of pyrazinamide in acidic media, with optimized pH of 6.0 at an operational potential of − 0.82 V (vs. SCE). The transmission electron microscopy results for the fabricated surfaces demonstrated the formation of nanoscale structures, representing successful electrodeposition and electro-polymerization processes to modify the glassy carbon electrode surface. Moreover, these results showed a linear electrochemical response to pyrazinamide within the concentration in the interval ranging from 3 to 24 µM, with the detection limit and limit of quantification of 0.0102 µM and 0.3658 µM. The fabricated sensor proved high selectivity and sensitivity for pyrazinamide, which made it possible to determine pyrazinamide in pharmaceutical formulations. Schematic illustration of the steps involved in the preparation of ionic liquid-reduced graphene oxide-silver nanoparticles-glassy carbon electrode for the electrochemical detection of pyrazinamide.