Amperometric cholesterol biosensor based on reconstituted cholesterol oxidase on boronic acid functional conducting polymers

An amperometric cholesterol biosensor was fabricated by electropolymerization method of conducting polymers on pencil graphite electrode (PGE) after which apo-cholesterol oxidase (apo-ChOx) was immobilized onto a flavin adenine dinucleotide (FAD) monolayer by reconstitution method. In this study two well-known and widely used materials in the field of biosensors thiophene-3-boronic acid and 3-aminophenyl boronic acid were electropolymerized onto PGE and modified with cholesterol oxidase. Electrochemical performance of modified electrodes and their properties were compared. Based on the results, thiophene-3-boronic acid based electrode shows sensitivity 10 times higher response than that of one based on 3-aminophenyl boronic acid. The effect of pH and temperature were assessed as well the reusability and stability of the fabricated biosensor were discussed.