A new protocol for the carboxylic acid sidewall functionalization of single-walled carbon nanotubes

► Two approaches for covalent attachment of COOH groups to the side-walls of SWNTs. ► A simple one-pot entry into the formation of benzoic acid moieties. ► Formation of benzothiomorpholides grafted to SWNTs via Willgerodt-Kindler reaction. ► Thioamides as useful link for covalent bonding between SWNTs and biological systems. ► Characterization of SWNTs by FT-IR, UV/vis, TGA, SEM, XPS and Raman techniques.