ELECTROCHEMICAL BIOSENSING PLATFORM UTILIZING GRAPHITIC CARBON NITRIDE-COPPER SULFIDE NANOHYBRID FOR SENSITIVE TRICHLORFON DETECTION

Abstract

Trichlorfon (TF) is considered the most frequently used organophosphorus compound among all compounds used for agricultural purposes. As such, TF can be quite effective in controlling insects that damage crops in several different ways. However, TF is toxic, and when individuals consume food contaminated with TF, it inhibits acetylcholinesterase, leading to a massive buildup of neurotransmitters at nerve synapses, ultimately disrupting normal nerve signal transmission and potentially causing severe neurological disorders. To address this problem, we have created a rapid, low-cost electrochemical biosensor using acetylcholinesterase (AChE) to detect the organophosphate pesticide (TF) via a g-C3N4/CuS-based nanocomposite. Electrostatic interactions between the g-C3N4/CuS nanocomposite enhance electron transfer to the electrode surface, thereby facilitating the covalent immobilization of AChE onto the electrode, with glutaraldehyde as a cross-linker to prevent enzyme leaching. Biosensor (AChE/g-C3N4/CuS/ITO) demonstrated an ultrahigh sensitivity toward TF over the linear range 0.1 pM - 1 µM. The developed biosensor showed stability, interference capability, good reproducibility and improved sensitivity. These characteristics enabled us to successfully detect TF in two real samples: apple and cucumber.