Acetylcholinesterase - Choline oxidase biosensor for pirimicarb determination

Abstract

A biosensor for the determination of pirimicarb was constructed by the co-immobilization of acetylcholinesterase and choline oxidase on a derivatised polyethersulfone membrane. The membrane was applied to an Universal Sensors electrode base system and the hydrogen peroxide formation was monitored upon addition of acetylcholine to an appropriately chosen buffer where the biosensor was dipped. The hydrogen peroxide is the product of the hydrolysis of choline, catalysed by cholineoxidase. Choline was formed by the action of acetylcholinesterase on acetylcholine. Pirimicarb inhibits these reactions and that fact can be used to determine its concentration. A calibration plot for pirimicarb was obtained.