Conductive poly(bromophenol red) film coated graphene oxide-ZnO nanocomposite modified electrode for enzymeless voltammetric determination of ethyl-paraoxon

Abstract

This work proposes a sensitive and nonenzymatic electrochemical platform for the cyclic voltammetric determination of ethyl-paraoxon (E-POX) at a poly-bromophenol red (poly(BPR) film coated graphene oxide (GO) and ZnO nanocomposite modified glassy carbon electrode (poly(BPR)@GO-ZnO/GCE). The incorporation of poly(BPR) matrix with GO-ZnO nanocomposite provides a considerable synergistic effect for the voltammetric determination of E-POX by providing a large surface area, more active sites, and high conductivity. The results showed that the poly(BPR)@GO-ZnO/GCE exhibits two linear response ranges from 0.10–3.0 µM and 5.0–200 µM with a limit of detection (LOD) of 31 nM and a high sensitivity of 5259 μA mM⁻¹ cm⁻². Real-world applicability of designed platform was successfully tested in agricultural (tomato and cucumber) and tap water samples, and acceptable recovery values (98.1–114.2 %) were obtained. It is concluded that the proposed platform (poly(BPR), GO, and ZnO) may bring remarkable approaches to the future fabrication of electrochemical sensors.