Controlled precipitation of solubilized carbon nanotubes by delamination of DNA.

Polyaromatic molecules, such as rhodamine 6G and methylene blue, were found capable of precipitating DNA-solubilized single-walled carbon nanotubes from solution through a competitive binding mechanism whereby DNA is displaced from the nanotube surface, allowing the nanotubes to rebundle. This delamination of DNA also occurred when complementary oligonucleotides were used to hybridize specifically to the DNA coating on the nanotubes. These findings were expanded to include techniques for controlled desolubilization and to provide additional elucidation into the interaction of SWNTs and noncovalent solubilizing agents.