DNA-Directed Assembly of Nanophase Materials: An Updated Review - DNA Nanotechnology: From Structure to Function - page 167

Fig. 8.9 Grafting highly hybridizable DNA tails on SWNTs for DNA-programmable assembly
(Copyright (2007) Wiley. Used with permission from Ref. [ 57 ])

rigidity and non-adsorptive nature as a double-stranded DNA (bases are well stacked
and not easily accessible from outside). In addition, the very rich surface charges of
the DNA-wrapped SWNT would contribute to repel the tail strand from approaching
the SWNT. Consequently, the short (16 bases) hybridization tail would have a
relatively weak adsorption on the SWNT, which if existed was not enough to
overcome the electrostatic and steric hindrances mentioned above. Therefore, the
grafted DNA tail on the SWNT should, for most of the time, remain in a tethered,
moving and unadsorbed state, favoring its fast hybridization kinetics. This was
based on the fact that large aggregates of SWNTs were formed within minutes
when two parts of SWNTs bearing complementary DNA tails were combined. In
contrast, a tail-free strategy required tens of minutes or more to achieve similar
hybridization results. AFM imaging evidenced that the as-formed SWNT aggregates
could be as large as up to 10 m, representing a highly efficient hybridization