Sensitive biosensor for choline and acetylcholine involving fast immobilization of a bienzyme system on a disposable membrane

A biosensor was prepared for the determination of choline or acetylcholine by co-immobilizing choline oxidase and cholinesterase on a chemically preactivated membrane ready for use. This rapid procedure allows the coupling to be performed in a few minutes. The determination is based on the electrochemical detection of enzymatically generated hydrogen peroxide. This sensor has a detection limit of 5 × 10^?8 M. The response was obtained in 2 min and was linear up to 2 × 10^?5 M.