Gold coated optical fibers as three-dimensional electrodes for microfluidic enzymatic biofuel cells: Toward geometrically enhanced performance.

For the first time, we report on the preliminary evaluation of gold coated optical fibers (GCOFs) as three-dimensional (3D) electrodes for a membraneless glucose/O2 enzymatic biofuel cell. Two off-the-shelf 125 μm diameter GCOFs were integrated into a 3D microfluidic chip fabricated via rapid prototyping. Using soluble enzymes and a 10 mM glucose solution flowing at an average velocity of 16 mm s(-1) along 3 mm long GCOFs, the maximum power density reached 30.0 ± 0.1 μW cm(-2) at a current density of 160.6 ± 0.3 μA cm(-2). Bundles composed of multiple GCOFs could further enhance these first results while serving as substrates for enzyme immobilization.