Selective Extraction of Carbon Nanotube Enantiomers By Specific DNA Sequences

Aqueous two-phase extraction (ATPE) is a robust and cost-effective technique recently demonstrated to separate a broad range of semiconducting and metallic single-wall carbon nanotube (SWCNT) species. We find that the partitioning of DNA-wrapped carbon nanotubes is highly sequence dependent and can further be controlled by the addition of salts and polymers. A comprehensive search of over 300 individual sequences was conducted, leading to the isolation of 20 individual SWCNT species. We apply circular dichroism to additionally show that each purified species is enantiomerically enriched. Enantiomeric differentiation by DNA is highlighted by a specific sequence which is able to isolate both enantiomers of the (6,5) species in record high purity.