Measurement of Nitrate Concentration in Aqueous Media Using an Electrochemical Nanosensor Based on Silver Nanoparticles-Nanocellulose/Graphene Oxide

Nitrate pollution is at the forefront of groundwater contamination which poses serious environmental and public health hazards. Nitrate is usually released in solution from agricultural activities and finds its way into groundwater resources. The objective of the present study was to determine, accurately concentrations of nitrate ions in water samples from the environment using sensitive electrochemical methods. For this purpose, a modified glassy carbon electrode modified with a nanocomposite consisting of silver nanoparticles, nanocellulose, and graphene oxide (Ag/NC/GO-GCE) was used. The characterization of the nanocomposite was investigated using scanning electron microscope (SEM), X-Ray diffraction (XRD), and electrochemical impedance spectroscopy (EIS). The modified Ag/NC/GO-GCE electrode was used as nanosensor for the electrocatalytic determination of nitrate using the voltammetric method. The effects of the parameters of scan rate, pH, and different nitrate concentrations were studied and the optimum conditions were obtained. A limit of detection of 0.016 µM (S/N=3) was found in the linear range of 0.005 to 10 mM nitrate. The Ag/NC/GO-GCE electrode exhibited a synergistic effect toward voltammetric determination of nitrate in the presence of graphene oxide, nanocellulose, and silver nanocatalyst. The nanosensor developed here showed excellent sensitivity, selectivity, and stability toward nitrate determination in aqueous solutions without any significant interference.