Patent ID: 8501152

Claim:
A method of radiolabeling carbon nanotubes comprising one or more surface carboxyl groups, characterized in that it comprises at least the following steps: a) a step of substituting the surface carboxyl groups with radiolabeled nitrile groups, consisting in reacting, in an organic solvent, said carbon nanotubes with a carbon 13 radiolabeled or carbon 14-radiolabeled cyanide, in the presence of a palladium catalyst, so as to result in radiolabeled carbon nanotubes comprising, at the surface, one or more carbon 13 labeled or carbon 14-labeled nitrile groups; and b) a step of hydrolyzing the nitrile group(s), consisting in reacting, in an organic solvent or an aqueous organic mixture, the carbon nanotubes obtained above in step a) with an acid or a base so as to result in radiolabeled carbon nanotubes comprising, at the surface, one or more carboxyl groups in which the carbon atom bearing the acid function is a carbon 13 or carbon 14 atom.