Multifunctional carbon nanotubes with nanoparticles embedded in their walls

Controlled amounts of nanoparticles ranging in size and composition were embedded in the walls of carbon nanotubes during a template-assisted chemical vapour deposition (CVD) process. The encapsulation of gold nanoparticles enabled surface enhanced Raman spectroscopy (SERS) detection of glycine inside the cavity of the nanotubes. Iron oxide particles are partially reduced to metallic iron during the CVD process giving the nanotubes ferromagnetic behaviour. At high nanoparticle concentrations, particle agglomerates can form. These agglomerates or larger particles, which are only partially embedded in the walls of the nanotubes, are covered by additional carbon layers inside the hollow cavity of the tube producing hillocks inside the nanotubes, with sizes comparable to the bore of the tube.