Coaxial nanowires consisting of a concentric layer of polypyrrole uniformly coated onto individual aligned nanotubes have provided a novel template for making glucose sensors with a large amount of enzyme electrochemically entrapped into the ultra thin polypyrrole (PPy) film. The aligned structure of carbon nanotubes plays an important role for glucose determination at lower anodic potential with a high sensitivity and selectivity. In addition, the use of aligned, highly accessible three-dimensional carbon nanotube arrays for oxidizing biomolecules is also presented in this paper.