Nanocrystalline Titanosilicate–Acetylcholinesterase Electrochemical Biosensor for the Ultra‐Trace Detection of Toxic Organophosphate Pesticides

In this work, nanocrystalline titanosilicate and ZSM‐5 were synthesized in the presence of propyltriethoxy silane as an additive. Electrochemical biosensors based on nanocrystalline zeolites were fabricated through the covalent immobilization of the enzyme acetylcholinesterase for the ultra‐trace detection of toxic organophosphate pesticides such as malathion, parathion methyl, monocrotopos, and dichlorvos. The results show that, among the zeolite‐based biosensors investigated in this study, the nanocrystalline titanosilicate‐based acetylcholinesterase biosensor exhibited the highest electrocatalytic activity. The nanocrystalline titanosilicate‐based acetylcholinesterase biosensor exhibited excellent sensitivity, selectivity, stability, linear range, and limit of detection. The analytical performance of the developed sensor was demonstrated in the determination of these pesticides in a range of real samples (apples, cabbages, tap water, and river water) with satisfactory recovery.