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Applied Biochemistry and Biotechnology, Vol.74, No.1, 1-12, 1998
Covalently immobilized choline oxidase and cholinesterases on a methacrylate copolymer for disposable membrane biosensors
Bienzymatic sensors for the determination of esters of choline were prepared by covalent co-immobilization of cholinesterases and choline oxidase on polymer membranes, obtained by radiation-induced copolymerization of 2-hydroxyethyl methacrylate and glycidyl methacrylate at low temperature. Optimization of the covalent attachment of choline oxidase and acetyl- or butyrylcholinesterase to copolymer was explored. The enzyme-modified polymers were applied on platinum electrodes to form amperometric sensors, based on the electrochemical detection of enzymatically developed hydrogen peroxide. Acetyl-, acetylthio-, butyryl-, and butyrylthiocholine contents in standard solutions were measured, and linear calibration curves were determined. Temperature and pH effects on the electrochemical response are described.
Keywords:AMPEROMETRIC SENSORS, GLUCOSE-OXIDASE, CARBON-FIBER;ACETYLCHOLINE, PESTICIDES, ENZYMES, POLYMERS, MICROELECTRODES;ELECTRODE