Development of biosensor by direct covalent immobilization of glucose oxidase on boron doped diamond film

A direct covalent immobilization of glucose oxidase was performed on carboxylated boron doped diamond (BDD) film using 1-Ethyl-3-(dimethylaminopropyl)-carbodiimide (EDC). The carboxylated BDD film deposited using the microwave plasma CVD was obtained by the chemical treatments of oxidization and hydrolysis. The immobilized glucose oxidase was confirmed by a spectrophotometric assay to have the enzyme activity on the BDD film. The activity of the immobilized glucose oxidase indicated long term stability. In addition, the glucose concentration was electrically detected using a redox reaction to the activity of the immobilized glucose oxidase during electrochemical measurements. Carboxylated BDD film allows a short and simple attachment of biomolecules, and leads to development of biomolecules-based biosensors or bio-chips.