Preparation of a new amperometric biosensor for cholesterol determination

In this study, a new amperometric biosensor for determination of cholesterol oxidase was developed. While pyrrole is being electropolimerized, polyvinyl sulphonate has been carried on the electrode surface together with the enzyme, meanwhile the enzyme has been immobilized via the entrapment method. As a result, Pt/polypyrrole-polyvinylsulphonate-enzyme electrode has been prepared. Cholesterol detection is based on the oxidation of hydrogen peroxide at +0.40V produced by the enzymatic reaction on the enzyme electrode surface. The effects of pH and temperature on the response of the cholesterol biosensor were investigated. The linear working range of biosensor was 4.10-5 ? 2.10-4 of cholesterol concentration. Value of KM and Vmax immobilized enzyme were estimated respectively. Reuse number and storage stability were determined of the biosensor. Determination of cholesterol was carried out in biological fluid ( in blood) by biosensor. Interference effects were investigated on the amperometric response of the biosensor.