Ultra-sensitive zinc cobaltate assembled on N-rich carbon nitride electrochemical sensor for the detection of paraquat in food samples

Abstract

Background

Paraquat (PQ) from agricultural waste cause contamination in water bodies, groundwater, soil, and foods has received increasing attention regarding health safety. On-site-based detection is much needed along with rapid results, selectivity and sensitivity, which can be achieved through an electrochemical-based sensor.

Methods

This work provides, an electrochemical sensor based on zinc cobaltite (ZnCo₂O₄) nanostructure strongly attracted through electrostatic interaction with the carbon nitride (C₃N₅; CN) nanosheets modified on a glassy carbon electrode (GCE) for the determination of paraquat (PQ). The strong immobilization of ZnCo₂O₄ over CN₂ on GCE synergistically shows excellent sensing of PQ due to high interfacial charge transfer effect.

Significant findings

In addition, the electrochemical studies were performed using CV and DPV analysis which exhibits a good limit of detection (7.6 nM) and sensitivity (0.201 µA cm^-2) towards PQ detection. Furthermore, the modified electrode was applied practically in real food samples for PQ detection with excellent recoveries.