Carbohydrate coating of carbon nanotubes for biological recognition

We have demonstrated that multi-walled carbon nanotubes (MWNTs) coated with a carbohydrate-carrying polymer for use as biological recognition signals can be easily prepared by a non-covalent method via hydrophobic interactions. Fluorescence observation by confocal laser scanning microscopy showed that the carbohydrate-carrying polymers were densely localized around the MWNTs. To evaluate biological recognition affinity, interactions of the MWNTs with lectins were examined by binding tests. The resultant MWNTs were found to acquire a selective binding affinity to the corresponding lectin without a non-specific interaction. On the other hand, bare MWNTs non-specifically interacted with lectins. These results showed that the MWNTs coated with a carbohydrate-carrying polymer have biological recognition signals. Modification of carbon nanotubes with various carbohydrate chains will be a useful protocol for molecular designs of biomaterials, nanoarchitecture and biosensors.