Electrochemical fabrication and characterization of CoOx nanoparticle-modified glassy carbon electrode for sensitive detection of glyphosate

Abstract

The quantification of glyphosate in aqueous systems is vital for environmental preservation and public health safety, enabling the tracking of agricultural runoff and supporting data-driven regulatory measures. This research details the development and construction of an electrode modified with cobalt oxide nanoparticles (CoOx) to serve as a high-sensitivity platform for the electrochemical sensing of glyphosate. Synthesis of the CoOx nanoparticles was followed by their electrochemical deposition onto a glassy carbon (GC) substrate through cyclic voltammetry under predetermined optimal parameters. The structural and electrochemical characteristics of the resulting modified electrodes were thoroughly analyzed using a suite of analytical methods: field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). Electrochemical assessments revealed that the electrodes possessed significantly enhanced activity, which was directly attributed to the incorporated nanoparticles. Crucially, both CV and EIS analyses verified a potent affinity and interaction between the glyphosate molecules and the CoOx nanomaterial. EIS measurements further established a linear correlation between the charge transfer resistance and glyphosate concentrations spanning from 0.15 to 0.9 μM, thereby confirming the sensor's effective detection mechanism. The constructed biosensor demonstrated a sensitivity of 6.5 μA and a linear response across the 0.15–0.9 μM glyphosate range, achieving a calculated detection limit (LOD) of 0.8 μM. Collectively, these results underscore the efficacy of the CoOx-based electrode as a promising and robust tool for monitoring glyphosate contamination in water, thereby aiding initiatives aimed at ensuring water quality and safeguarding community health. © 2025