DNA-Controlled Carbon Nanotube Purification in Polymer Aqueous Two-Phase Systems

Sorting single-wall carbon nanotubes (SWCNTs) of different chiralities is both scientifically interesting and technologically important. Polymer aqueous two-phase (ATP) extraction has been demonstrated recently as a very effective way to achieve nanotube sorting. In this work, we report a systematic study of sequence-dependent partition of DNA-wrapped SWCNTs in several polymer ATP systems. This unique approach of combining DNA sequence and polymer ATP system enabled the purification of many single-chirality SWCNT species at high purity. In addition, the DNA-controlled partition of SWCNTs in ATP system suggests the sensitive dependence of hydration energy on the exact spatial distribution of hydrophilic groups which are determined by the DNA sequence and the SWCNT chirality (n,m).