Acetylcholinesterase immobilization on 3-mercaptopropionic acid self assembled monolayer for determination of pesticides

Studies on the immobilization of acetylcholinesterase onto a SAM gold electrode and the use of the fabricated biosensor for the determination of carbaryl and parathion are presented. The influence of pH, ionic strength, enzyme loading and concentration of glutaraldehyde on the response of the biosensor was investigated. The amperometric biosensor developed in this study provided linearity to parathion and carbaryl in the 2.0 a 30.0 x 10(-6) mol L-1 concentration range. The detection limits under the optimum working conditions were found to be 9.3 mu g L-1 for parathion and 9.0 mu g L-1 for carbaryl. The enzyme electrode was found to be stable for 7 days.