ENTRAPMENT OF ENZYMES IN ELECTROPOLYMERS FOR BIOSENSORS AND GRAPHITE FELT BASED FLOW-THROUGH ENZYME REACTORS

Immobilization of glucose oxidase in conducting polymers electrochemic ally generated from pyrrole, N-methylpyrrole, aniline and orthophenyle ne diamine on platinum surfaces was used to construct amperometric glu cose biosensors. High sensitivity was obtained with a sensor utilizing polymerized o-phenylene diamine as entrapment matrix. This polymer, a s well as polypyrrole, was used to prepare a new type of enzyme reacto rs with immobilized glucose or lactate oxidase by depositing enzyme-po lymer layers on pieces of graphite felt. Mounted into a column, the fe lt can then be applied as an enzyme reactor in a flow system. It can e ither be used as working electrode itself in an electrochemical detect ion system or be combined with a separate detector. A microelectrode a rray was chosen as an example of the latter. With this system, detecti on limits lower than 500 mu M and a linear range up to 10 mM were obta ined for glucose and a detection limit lower than 50 mu M and a linear range up to 1 mM for lactate, respectively.