Highly Sensitive Detection of Carbaryl Pesticides Using Potentiometric Biosensor with Nanocomposite Ag/r-Graphene Oxide/Chitosan Immobilized Acetylcholinesterase Enzyme
Mashuni Mashuni, Halimahtussaddiyah Ritonga, M. Jahiding, Bonni Rubak, Fitri Handayani Hamid
Abstract
Novel, sensitive, selective, efficient and portable electrochemical biosensors are needed to detect residual contaminants of the pesticide 1-naphthyl methylcarbamate (carbaryl) in the environment, food, and essential biological fluids. In this work, a study of nanocomposite-based Ag reduced graphene oxide (rGO) and chitosan (CS) that optimise surface conditions for immobilisation of acetylcholinesterase (AChE) enzyme to improve the performance of catalytic biosensors is examined. The Ag/rGO/CS nanocomposite membrane was used to determine carbaryl pesticide using a potentiometer transducer. The AChE enzyme-based biosensor exhibits a good affinity for acetylthiocholine chloride (ATCl). It can catalyse the hydrolysis of ATCl with a potential value of 197.06 mV, which is then oxidised to produce a detectable and rapid response. Under optimal conditions, the biosensor detected carbaryl pesticide at concentrations in the linear range of 1.0 × 10−8 to 1.0 μg mL−1 with a limit of detection (LoD) of 1.0 × 10−9 μg mL−1. The developed biosensor exhibits a wide working concentration range, detection at low concentrations, high sensitivity, acceptable stability, reproducibility and simple fabrication, thus providing a promising tool for pesticide residue analysis.