Gold-substrate-enhanced scanning electron microscopy of functionalized single-wall carbon nanotubes

Functionalized regions of a single-wall carbon nanotube were resolved by scanning electron microscopy at 1 kV when the functionalized nanotube was placed on a gold substrate. Beam energy and substrate dependence studies suggest that the sharp imaging contrast arises from an increase in the yield of secondary electrons as compared to gold due to covalent modification of the nanotube. Using this surprisingly simple technique, it becomes possible to rapidly map surface functionalization on individual carbon nanotubes with a spatial resolution better than 10 nm. This new functionalization imaging technique may facilitate spatial control of surface chemistry and defect engineering in carbon nanomaterials.