Stalling Behaviour of Chloride ions: A Non-enzymatic Electrochemical Detection of α-Endosulfan using CuO Interface

Abstract Excessive and unsafe usage of pesticides lead to adverse effect on human beings, plants, animals and aquatic life. Endosulfan, categorized as class-I pesticide by World Health Organization, is a highly toxic pesticide, which is currently being used across countries although it has been banned. In this context, a non-enzymatic electrochemical sensor with copper oxide interface has been developed to detect α-endosulfan in water samples. Hydrothermal synthesized CuO microspheres were characterized using X-ray Diffractometer, Scanning Electron Microscope and X-ray Photoelectron Spectrometer. CuO micro-interface modified gold working electrode along with Pt counter electrode and Ag/AgCl reference electrode were employed to carry out Differential Pulse Voltammetry (DPV) and amperometry studies to detect the presence of α-endosulfan in water. The stalling behaviour of chloride ions present in α-endosulfan in reducing the current intensity confirmed the presence and concentration of α-endosulfan. The impedance variation for the varying concentration of α-endosulfan confirmed the proposed sensing mechanism. The sensor showed a linear range of 4–20 nM, and sensitivity of 0.03 μA nM −1 . The relative standard deviation for the repeatability and reproducibility was 1.69%. The stability of the developed biosensor was 80.93% for 15 days.