Voltammetric simultaneous quantification of p-nitrophenol and hydrazine by using magnetic spinel FeCoO nanosheets on reduced graphene oxide layers modified with curcumin-stabilized silver nanoparticles.

A sensor based on a screen-printed carbon electrode loaded with curcumin-stabilized silver nanoparticle-coated reduced graphene oxide magnetic spinel (FeCoO) nanosheets was constructed. The electrocatalytic activity of the electrode enables sensitive simultaneous quantification of hydrazine and p-nitrophenol. The respective working potentials typically are at +0.15 V for hydrazine and at -0.75 V for p-nitrophenol (both vs. pseudo Ag/AgCl), and the detection limits are 23 nM and 18 nM (at S/N = 3). Good selectivity, repeatability, reproducibility and storage stability are shown. The sensor was used to analyze spiked samples of river water and industrial wastewater. Graphical abstract Schematic of an electrochemical sensor for simultaneous quantification of hydrazine and 4-nitrophenol in various natural and wastewater samples. The electrocatalyst in this sensor is composed of graphene oxide nanosheets modified with a magnetic spinel of type FeCoO and os curcumin-stabilized silver nanoparticles.