We are aware of an issue with certificate availability and are working diligently with the vendor to resolve. The vendor has indicated that, while users are unable to directly access their certificates, results are still being stored. Certificates will be available once the issue is resolved. Thank you for your patience.

(92g) Specific DNA Sequences for High Purity Carbon Nanotube Enantiomer Separation

Ao, G., National Institute of Standards and Technology
Fagan, J. A., National Institute of Standards and Technology
Zheng, M., National Institute of Standards and Technology

Despite the remarkable electrical, thermal, mechanical, and optical properties of carbon nanotubes (CNTs), polydispersity has been one of the major challenges limiting their fundamental research and technological development. In addition, separating carbon nanotube enantiomers is of great scientific interest since it provides important information into the mode of DNA binding and molecular recognition towards specific nanotube structures. Polymer aqueous two-phase (ATP) extraction has been recently demonstrated as an effective technique to sort carbon nanotubes of different chiralities in high purity and yield. The spontaneous partition of single-stranded DNA-wrapped single-wall carbon nanotubes (ssDNA-SWCNTs) in a given ATP system is strongly sequence-dependent. Additionally, circular dichroism (CD) spectroscopy shows that purified semiconducting and metallic nanotubes are also enantiomer enriched. In this work, we have conducted an exhaustive screening of a 12-mer DNA library using a specific DNA sequence pattern. To our surprise, this new pattern enabled the identification of a super-sequence which can recognize and separate both enantiomers of a single chirality (6,5) species in high purity and yield, as well as the isolation of multiple high purity enantiomers in an ATP system.