Deoxyribonucleic acid (DNA) and single-walled carbon nanotubes (SWCNTs) are prototypical onedimensional structures, the former in chemical biology and the latter in nanotechnology [1-3]; a plethora of applications currently envisage carbon nanotubes as next-generation encapsulation media for biological polymers, such as proteins and nucleic acids [1]. The interactions between both have been the subject of intense investigation, nonetheless, the corresponding molecularlevel phenomena remain rather unexplored. Recently we have shown that, given a sufficiently large hydrophobic nanotube, the confinement of a DNA dodecamer is thermodynamically favourable under physiological environments (134 mM, 310 K, 1 bar), leading to DNA@nanotube hybrids with lower free energy than the unconfined biomolecule [4]. To accommodate itself within the D = 4nm nanopore, DNA’s end-to-end length increases from 3.85 nm up to approximately 4.1 nm, via a 0.3 nm elastic expansion of the strand termini. The canonical Watson-Crick H-bond network is essentially preserved throughout encapsulation, showing that contact between the DNA dodecamer and the hydrophobic carbon walls results in minor rearrangements of the nucleotides H-bonding. A diameter threshold of 3 nm was established below which encapsulation is inhibited.
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