Molecularly Ordered Bioelectrocatalytic Composite Inside a Film of Aligned Carbon Nanotubes

Molecularly ordered composites of polyvinylimidazole‐[Os(bipyridine) 2 Cl] (PVI‐[Os(bpy) 2 Cl]) and glucose oxidase (GOD) are assembled inside a film of aligned carbon nanotubes. The structure of the prepared GOD/PVI‐[Os(bpy) 2 Cl]/CNT composite film is entirely uniform and stable; more than 90% bioelectrocatalytic activity could be maintained even after storage for 6 d. Owing to the ideal positional relationship achieved between enzyme, mediator, and electrode, the prepared film shows a high bioelectrocatalytic activity for glucose oxidation (ca. 15 mA cm −2 at 25 °C) with an extremely high electron‐transfer turnover rate (ca. 650 s −1 ) comparable to the value for GOD solutions, indicating almost every enzyme molecule entrapped within the ensemble (ca. 3 × 10 12 enzymes in a 1 mm × 1 mm film) can work to the fullest extent. This free‐standing, flexible composite film can be used by winding on a needle device; as an example, a self‐powered sugar monitor is demonstrated.