Described are single-walled metal oxide nanotubes having a plurality of organic functional units or moieties bonded generally in a covalent manner to the inner wall of the single-walled nanotubes. Functionalization of the single-walled metal oxide nanotubes is performed in a single-step during synthesis of the nanotubes. The organic functional units are found dispersed throughout the length of the inner wall and not sterically hindered or contained at only the mouth or ends of the single-walled metal oxide nanotubes.