Efficient enzymatic CO2 reduction reaction on carbon nanotubes.

An original 1-acetato-4-(1-pyrenyl)-1,4,7-tria- zacyclononane (AcPyTACN) was synthesized for the immobilization of a His-tagged recombinant CODH from Rhodospirillum rubrum (RrCODH) on carbon-nanotube electrodes. The strong binding of the enzyme at the Ni-AcPyTACN complex affords a high current density of 4.9 mA cm-2 towards electroenzymatic CO2 reduction and a high stability of more than 6 × 106 TON when integrated on a gas-diffusion bioelectrode.