Reversible sidewall osmylation of individual carbon nanotubes

Sidewall osmylation of individual metallic single-walled carbon nanotubes has been achieved by exposing the tubes to osmium tetroxide vapor under UV photoirradiation. The covalent attachment of the osmium oxide leads to an increase in the electrical resistance by up to several orders of magnitude. The cycloaddition product can be cleaved by UV light in vacuum or under an oxygen atmosphere, whereby the original resistance is restored.