An Acetylcholinesterase Inhibition-Based Biosensor for Aflatoxin B1 Detection Using Sodium Alginate as an Immobilization Matrix
Amani Chrouda, Khouala Zinoubi, Raya Soltane, Noof Alzahrani, Gamal Osman, Youssef O. Al‐Ghamdi, Sameer H. Qari, Albandary Al Mahri, Faisal K. Algethami, Hatem Majdoub, Nicole Jaffrézic‐Renault
Abstract
In this study, we investigated a novel aflatoxin biosensor based on acetylcholinesterase (AChE) inhibition by aflatoxin B1 (AFB1) and developed electrochemical biosensors based on a sodium alginate biopolymer as a new matrix for acetylcholinesterase immobilization. Electrochemical impedance spectroscopy was performed as a convenient transduction method to evaluate the AChE activity through the oxidation of the metabolic product, thiocholine. Satisfactory analytical performances in terms of high sensitivity, good repeatability, and long-term storage stability were obtained with a linear dynamic range from 0.1 to 100 ng/mL and a low detection limit of 0.1 ng/mL, which is below the recommended level of AFB1 (2 µg/L). The suitability of the proposed method was evaluated using the samples of rice supplemented with AFB1 (0.5 ng/mL). The selectivity of the AChE-biosensor for aflatoxins relative to other sets of toxic substances (OTA, AFM 1) was also investigated.