SILVER NANOPARTICLE-MODIFIED GRAPHITE PENCIL ELECTRODE FOR SENSITIVE ELECTROCHEMICAL DETECTION OF CHLORIDE IONS IN PHARMACEUTICAL FORMULATIONS

Abstract

For the first time, silver nanoparticles (AgNPs) were fabricated with graphite pencil electrode (GPE) by immersing a bare hard black pencil (HB pencil) in AgNO3 solution mixed with extract Quercus infectoria solution, followed by placing directly against to UV lamp (254 nm) and kept for 30 min. Silver modified-GPEs were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectrometer (EDX). The silver nanoparticles fabricated with graphite pencil electrode (AgNPs–GPE) showed excellent selectivity to chloride ion, as well as excellent reproducibility, together with it has several advantages such as sensitivity, simplicity, low cost, green, and fast response. The maximum oxidation cyclic voltammogram current of the AgNPs-PGE was found at 160 mV. The linear range of chloride ions detection is between (0.8-52 mmol L-1), and the limit of detection (LOD) of chloride ions is 0.041 mmol L-1. Finally, the Silver fabrication electrode was used to determine the chloride ion concentration in drugs, such as phenylephrine, metformin, procaine, and dopamine formulated with hydrochloride, and satisfactory results were obtained.