A Novel Acetylcholinesterase-Based Electrochemical Biosensor Using g-C3N4@MoS2 Nanohybrid for the Detection of Trichlorfon

Organophosphorus pesticides are commonly employed in agricultural fields due to their potent insecticidal properties and short environmental persistence. However, organophosphorus pesticides enter the human body through the food chain, surface, and groundwater, leading to irreversible damage to the nervous system. Therefore, monitoring the presence of organophosphorus pesticides in food is necessary to ensure human safety. Herein, an ultra-sensitive electrochemical biosensor has been prepared by using graphitic carbon nitride decorated molybdenum sulfide (g-C₃N₄@MoS₂) as a catalyst for the detection of organophosphorus pesticides, trichlorfon. The synergistic effect of g-C₃N₄@MoS₂ boosts the electron transfer across the electrode surface, further contributing to the immobilization of acetylcholinesterase (AChE) enzyme using glutaraldehyde as a crosslinking agent. At optimum conditions, the developed biosensor (AChE/g-C₃N₄@MoS₂/ITO) demonstrated a broad linear range (5–100 nM) with a low detection limit (LOD) of 2.1 nM obtained using the equation 3σ/S where σ is the standard deviation and S is the sensitivity of the bioelectrode. In addition, the AChE/g-C₃N₄@MoS₂/ITO biosensor exhibited good stability and reproducibility, with satisfactory results for real sample analysis of trichlorfon detection.