Organizing single-walled carbon nanotubes on gold using a wet chemical self-assembling technique

We provide a wet chemical approach for organizing randomly tangled single-walled carbon nanotubes (SWCNTs) on gold surfaces. The as-grown nanotubes were first chemically cut into short pipes and thiol-derivatized at the open ends. The ordered assembly of SWCNTs was made by their spontaneous chemical adsorption to gold via Au-S bonds. Tapping mode atomic force microscopy (AFM) images clearly show that the nanotubes have been organized on gold, forming a self-assembled monolayer structure with a perpendicular orientation. The adsorption kinetics of the nanotubes was very slow in comparison to conventional alkanethiols. The adsorption rate varied inversely with tube length. The nanotubes tend to form bundles as the adsorption propagates, following a nucleation adsorption mechanism. This work demonstrates that giant carbon nanotubes can be assembled on Au surfaces using wet chemistry similar to that exploited for small organic self-assembling species. We believe that assembled nanotube arrays will provide wide possibilities for applications.