Enzyme entrapment in electrically conducting polymers. Immobilisation of glucose oxidase in polypyrrole and its application in amperometric glucose sensors

A technique is described for the entrapment of glucose oxidase in a polypyrrole matrix electrochemically deposited on a printed platinum electrode. The enzyme activity incorporated into the polymer was quantified by spectrophotometric assay using a flow-through cell and found to be proportional to the activity in the electropolymerisation medium. Polymer-entrapped glucose oxidase electrodes can be operated as amperometric glucose sensors in the presence or absence of soluble mediators. These electrodes respond rapidly, reaching a steady state within 20–40 s, with the enzymatic response being current limiting. The potential of this new immobilisation technique to the development of biosensors is discussed.