Well defined mediatorless bioelectrocatalytic redn. of oxygen with high current densities of 0.8 mA cm- 2 was obtained on nanoporous gold electrodes modified with Myrothecium verrucaria bilirubin oxidase. A stable faradaic response was obsd. when the enzyme modified electrode was coated with a specifically designed electrodeposition polymer layer. The response of the enzyme electrode was only slightly inhibited by the addn. of F-.