Oxygen biosensor based on bilirubin oxidase immobilized on a nanostructured gold electrode

Gold disk electrodes modified with gold nanoparticles have been used as a scaffold for the covalent immobilization of bilirubin oxidase. The nanostructured bioelectrodes were tested as mediator-less biosensors for oxygen in a buffer that mimics the content and the composition of human physiological fluids. Chronoamperometry measurements showed a detection limit towards oxygen of 6 ± 1 μM with a linear range of 6-300 μM, i.e. exceeding usual physiological ranges of oxygen in human tissues and fluids. The biosensor presented is the first ever-reported oxygen amperometric biosensor based on direct electron transfer of bilirubin oxidase.This work was funded by the FP7 project “3D-Nanobiodevice” (NMP4-SL-2009-229255). We thank Novozymes A/S for the preparation of Myrothecium verrucaria BOx. M.P. acknowledges the 2009 Ramon y Cajal program from the Spanish MINECO.Peer reviewe