An amperometric sensor for choline and acetylcholine based on a platinum electrode modified by a co-crosslinked bienzymatic system

A fast-response and sensitive amperometric biosensor for choline and acetylcholine based on choline oxidase and acetylcholinesterase immobilised on a platinum electrode by co-crosslinking with bovine serum albumin and glutaraldehyde has been developed. The immobilisation procedure proved fast and simple, not requiring dedicated manipulation. Detection limits were in the sub-micromolar range and linearity extended over three concentration decades. After one month of discontinuous use, 70 % of the initial sensitivity was still observed. The response time was around 1 s for both analytes making the developed biosensor a suitable detector for flow injection analysis and high performance liquid chromatography