Chirality-pure carbon nanotubes show distinct complexation with recognition DNA sequences

Abstract Pure-chirality single-wall carbon nanotubes (SWCNTs) that are non-covalently complexed with recognition DNA sequences exhibit unique interaction behavior and hybrid stability in aqueous environments. The complexation of DNA-wrapped SWCNTs was found to be a strong function of both the DNA sequence and SWCNT chiral structure, highlighted by the distinct coating displacement of the same recognition DNA sequence from a pair of (6,5) enantiomers by a strong surfactant. A broad range of changes were observed for different DNA/SWCNT recognition pairs with surfactant exchange including the increase in nanotube photoluminescence intensity in the near-infrared (NIR) from 1.3 to 14.7-fold and time constants deduced from DNA displacement kinetics ranging from 9 s to 230 s. A large time constant of 230 s and a relatively small 4.4-fold increase in NIR emission intensity were obtained for the CTC3TC-(7,6) hybrid highlighting the vast potential of short DNA sequences for improved nanotube sorting and hybrid stability in aqueous environments. Additionally, CTC3TC-(7,6) was identified as the only hybrid to exhibit an increase in NIR fluorescence intensity in serum-containing cell culture media among all samples tested. Our results demonstrated unique optical properties and hybrid stability of DNA/SWCNT recognition pairs, providing a foundation for developing applications of chirality-pure SWCNTs.