Nitrogen-doped carbon nanotubes enhanced laccase enzymatic reactivity towards oxygen reduction and its application in biofuel cell

Nitrogen-doped carbon nanotubes (NCNTs) were designed for the immobilization and biosensing of proteins. The glutaraldehyde functionalized chitosan (GCS) was mixed with NCNTs to generate nanocomposites for enzyme immobilization. Laccase (Lac) or glucose oxidase (GOD) in GCS/NCNT nanocomposites displayed excellent enzymatic activity towards the reduction of oxygen or the oxidation of glucose. This led to elaboration of a glucose/air biofuel cell with a maximum power density of 21 μW cm− 2 at 0.2 V.

Nitrogen-doped carbon nanotubes (NCNTs) were designed for the immobilization of laccase and glucose oxidase for the elaboration of a glucose/air biofuel cell. The nitrogen doping accelerated the electron transfer from electrode surface to the protein, leading to the protein molecules in GCS/NCNTs that possessed higher electrocatalytic activity.Figure optionsDownload as PowerPoint slideHighlights
► Negative charges from nitrogen doping led to better hydrophilicity of GCS/NCNT nanocomposite.
► Laccase in nanocomposites exhibited an excellent enzymatic activity to the reduction of oxygen.
► The nitrogen doping accelerated the electron transfer from electrode to protein.
► The GCS/NCNT nanocomposite based glucose/air biofuel cell yields a high power output.
► The GCS/NCNT nanocomposite was a good matrix to integrate protein and electrode.