MXene Decorated Graphitic Carbon Nitride-based Electrochemical Biosensor for the Ultrasensitive Determination of...

Organophosphate pesticides have been widely used to protect crops from pests during growth and to maintain their quality after harvest. However, their residues and decomposition products may permeate the soil and water systems, eventually accumulating in food products and posing potential health and environmental concerns. Therefore, the development of a robust analytical technique to monitor these residues is crucial. Herein, a novel and highly efficient acetylcholinesterase (AChE) based electrochemical biosensing platform was constructed using MXene and graphitic carbon nitride (Ti₃C₂T_x@g-C₃N₄) as a substrate material for the rapid determination of trichlorfon (TF). The synergistic effect of Ti₃C₂T_x@g-C₃N₄ not only facilitates electron diffusion at the sensing interface but also enhances the electroactive surface area for AChE immobilization. The structural and morphological features of the Ti₃C₂T_x@g-C₃N₄ composite were characterized using various analytical techniques. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV) were employed to examine the electrochemical behaviour of the prepared biosensor. Under optimal conditions, the fabricated biosensor (AChE/M-Ti₃C₂T_x@g-C₃N₄/ITO) demonstrates a wide linear range (0.1 pM-1 µM) and a low detection limit (LOD) of 0.1 pM. Moreover, the biosensor shows good reproducibility, high anti-interference ability, and acceptable stability. Finally, the feasibility of developed biosensor was validated in real matrices (carrot, guava, and fenugreek) which exhibits the satisfactory recovery (91.9%-108.1%).