Functionalization of carbon nanotubes for biocompatibility and biomolecular recognition

The interface between biological molecules and novel nanomaterials is important to developing new types of miniature devices for biological applications. Here, the streptavidin/biotin system is used to investigate the adsorption behavior of proteins on the sides of single-walled carbon nanotubes (SWNTs). Functionalization of SWNTs by coadsorption of a surfactant and poly(ethylene glycol) is found to be effective in resisting nonspecific adsorption of streptavidin. Specific binding of streptavidin onto SWNTs is achieved by co-functionalization of nanotubes with biotin and protein-resistant polymers.