Cu0-doped graphitic carbon quantum dots for rapid electrochemical sensing of glyphosate herbicide in environmental samples

Abstract

A widely used herbicide, glyphosate (Glyp) is a major pollutant in the environment and can harm human health. To combat this, an electrochemical sensor has been developed using Cu0-doped graphitic carbon quantum dots (Cu0-OGQ) to detect trace amounts of Glyp in water, agricultural produce, vegetables, and fruits. The electrochemical behaviour of Cu0-OGQ was investigated using techniques such as differential pulse voltammetry (DPV), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). Cu0-OGQ has an electroactive area of 0.428 cm2, which is roughly 7 times greater than a bare glassy carbon electrode (0.0612 cm2) and 1.35 times larger than OGQ's (0.318 cm2). The developed Glyp sensor demonstrated under optimal experimental conditions a high sensitivity of 179.7 mu A ng/mL and a low detection limit (LOD) of 2.02 ng/mL (S/N = 10) in a broad concentration range of 0.01 mu M to 40 mu M. Based on selectivity experiments, the sensor has the potential to detect Glyp even in the presence of similar pesticides and other interferences like glucose, ascorbic acid, and various metal ions. The Cu0-OGQ sensor exhibited a recovery rate between 90 and 102 % in real sample detection of Glyp and maintained 95 % performance even after 30 days. Thus, it can be a reliable, selective, and stable tool for environmental analysis.