Single-step electrochemical fabrication of nanoporous gold film with reduced graphene oxide for carbendazim quantification in river water

Abstract

Carbendazim (CBZ) is a broad-spectrum fungicide used worldwide to control fungal infestations in various crops. However, its remarkable stability has raised concerns about accumulation in soils and aquatic environments, garnering significant attention from the analytical community. In this report, we propose a nanoporous gold electrode with reduced graphene oxide (NPGrGO) prepared according to a mold-assisted electrodeposition method, in which the gold film was deposited simultaneously with the reduction of graphene oxide on a gold microfiber surface for CBZ determination. The NPGrGO electrode exhibited a high density of edges with graphene sheets confined within the pores in the presence of gold nanoparticles. This unique configuration significantly enhances the electrochemical surface area and the roughness factor, directly influencing electrochemical measurements. Differential pulse voltammetry results show a linear behavior in the CBZ concentration range of 1 – 200 µmol L^-1 with a limit of detection of 0.3 µmol L^-1 and a limit of quantification of 1.0 µmol L^-1. Besides, the NPGrGO sensor also revealed excellent reproducibility (4.2%), repeatability (3.7%), and selectivity toward CBZ detection in the presence of other interfering molecules or ions. Finally, as proof of concept, the NPGrGO was used to determine CBZ in river water samples. Therefore, we have demonstrated a simple and rapid method for fabricating an NPGrGO electrochemical sensor, highlighting its significant potential for applications in environmental analysis.