Diazonium Functionalisation of Carbon Nanotubes for Specific Orientation of Multicopper Oxidases: Controlling Electron Entry Points and Oxygen Diffusion to the Enzyme.
We report the controlled orientation of bilirubin oxidases (BOD) from Myrothecium verrucaria on multiwalled carbon nanotubes (MWCNTs) functionalised by electrografting of 6-carboxynaphthalenediazonium and 4-(2-aminoethyl)benzenediazonium salts. On negatively charged naphthoate-modified MWCNTs, a high-potential (0.44 V vs. SCE) oxygen reduction electrocatalysis is observed, occurring via the T1 copper centre. On positively charged ammonium-modified MWCNTs, a low-potential (0.15 V) oxygen reduction electrocatalysis is observed, occurring through a partially oxidised state of the T2/T3 trinuclear copper cluster. Finally, chemically modified naphthoate MWCNTs exhibit high bioelectrocatalytic current densities of 3.9 mA cm(-2) under air at gas-diffusion electrode.
Univ. Grenoble Alpes, DCM UMR 5250, 38000, Grenoble, France.|CNRS, DCM UMR 5250, 38000, Grenoble, France.
Noémie
N
Lalaoui
Univ. Grenoble Alpes, DCM UMR 5250, 38000, Grenoble, France.|CNRS, DCM UMR 5250, 38000, Grenoble, France.
Michael
M
Holzinger
Univ. Grenoble Alpes, DCM UMR 5250, 38000, Grenoble, France. alan.le-goff@univ-grenoble-alpes.fr.|CNRS, DCM UMR 5250, 38000, Grenoble, France. alan.le-goff@univ-grenoble-alpes.fr.
Alan
http://orcid.org/0000-0002-6765-5859
A
Le Goff
Univ. Grenoble Alpes, DCM UMR 5250, 38000, Grenoble, France.|CNRS, DCM UMR 5250, 38000, Grenoble, France.
Serge
S
Cosnier
D002384:Catalysis; D003979:Diazonium Compounds / Q000737:chemistry*; D004058:Diffusion; D055664:Electrochemical Techniques; D004566:Electrodes; D004583:Electrons; D006999:Hypocreales / Q000201:enzymology; D008968:Molecular Conformation; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000737:chemistry*; D044925:Oxidoreductases Acting on CH-CH Group Donors / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry*; D013499:Surface Properties
D003979:Diazonium Compounds; D037742:Nanotubes, Carbon; D010088:Oxidoreductases; C024748:copper oxidase; D044925:Oxidoreductases Acting on CH-CH Group Donors; C042401:bilirubin oxidase; D010100:Oxygen
bilirubin oxidases; diazonium; metalloenzymes; nanotubes; oxygen reduction