HIGHLY SELECTIVE BIOSENSING OF LACTATE AT LACTATE OXIDASE CONTAINING RHODIUM-DISPERSED CARBON-PASTE ELECTRODES

A remarkably selective lactate biosensor, based on the immobilization of lactate oxidase within a rhodium-dispersed carbon paste is describe d. The effective catalytic action of the rhodium microparticles toward s the generated hydrogen peroxide or consumed oxygen allows tuning of the operating potential to a region where unwanted reactions are preve nted. Contributions from all major easily oxidizable substances are el iminated, without the need for membrane barriers or artificial electro n mediators. The detection limit is 1.5 x 10(-5) M and the response ti me is 8 s. A fast and sensitive now injection operation is illustrated .