Covalently linked DNA nanotubes.

The present study introduces an approach to prepare covalently linked DNA nanotubes. A circular DNA that includes at its opposite poles thiol and amine functionalities acts as the building block for the construction of the DNA nanotubes. The circular DNA is cross-linked with a bis-amide-modified nucleic acid to yield DNA nanowires, and these are subsequently cross-linked by a bis-thiolated nucleic acid to yield the DNA nanotubes. Alternatively, a circular DNA that includes four amine functionalities on its poles is cross-linked in one-step by the bis-thiolated nucleic acid to yield the nanotubes. The resulting nanostructures are stable and nonseparable upon heating.