We present novel metallic/bimetallic (Pt, Au-Pt) nanoparticle-decorated carbon nanotubes and bilirubin oxidase-decorated carbon nanotubes deposited on nano-tube buckypaper as promising supported electro-catalytic systems and as electrode material respectively for mixed-reactant biofuel cell applications at neutral pH. We found that the novel enzyme-decorated carbon nanotubes on nanotube buckypaper material is a promising cathode for glucose biofuel cells. It exhibited a high tolerance and catalytic activity resulting in higher current densities compared to carbon black based electrodes.