Detection of toxic cypermethrin pesticides in drinking water by simple graphitic electrode modified with Kraft lignin@Ni@g-C3N4 nano-composite†

Abstract

The detrimental effects of widespread pesticide application on the health of living organisms highlight the urgent need for technological advancements in monitoring pesticide residues at trace levels. This study involves the synthesis of a distinctive sensing material, KL@Ni@g-C₃N₄, which comprises nanocomposites of graphitic carbon nitride with Kraft lignin and nickel. The prepared samples were characterized using FT-IR, PXRD, TEM, SEM, and EDX techniques. The KL@Ni@g-C₃N₄ nanocomposite was drop-cast on a graphite electrode. Subsequently, this fabricated electrode was used to detect cypermethrin (CYP) residues in drinking water. The redox properties of the fabricated sensors were evaluated using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The limit of detection (LOD) of the fabricated sensor was determined to be 0.026 μg mL⁻¹, which is below the maximum residual limits of CYP in the environment (0.5 μg mL⁻¹) and within the acceptable range for food products (∼0.05 to 0.2 μg mL⁻¹). Therefore, this study proposes a promising alternative to conventional methods for detecting pesticides in drinking water.