Energetic Basis of Single-Wall Carbon Nanotube Enantiomer Recognition by Single-Stranded DNA

Hybrids of Single-stranded DNA and single-walled carbon. nanotubes (SWCNts) have proven to be very successful in separating various chiralities and, recently, enantiomers of carboh nanotubes using aqueous two-phase separation: This technique sorts objects based on small differences in hydration energy, which is related to corresponding small differences in structure, Separation by handedness requires that a given ssDNA sequence adopt different structures: on :the two SWCNT enantiomers. Here we study :the physical basis of such selectivity using a, coarse-grained model to compute the energetics of ssDNA-wrapped. around an-SWCNT. Our Model suggests that difference by handedness of the SWCNT requires spontaneous twist of the ssDNA backbone. We also show that differences depend sensitively on the choice of DNA sequence.