DNA tricked to act as nano-building blocks

an approach to DNA nanotube construction that provides control over their size and geometry, one rung at a time. Specifically, we constructed the first triangular and square-shaped DNA nanotubes that can be assembled in fully double-stranded or partially single-stranded forms.

McGill researchers have succeeded in finding a new way to manufacture nanotubes, one of the important building blocks of the nanotechnology of the future using DNA. The DNA nanotubes can be used as molds for metallic wires.

DNA strands are programmed to assemble into complex one- two- and three-dimensional structures. By incorporating synthetic molecules into such strands of DNA, the Sleiman group provided nature’s workhorse with further specific dialed-in structural and functional properties.

Using this method, Faisal Aldaye, Peggy Lo, Pierre Karam and Chris McLaughlin in the Sleiman and Cosa laboratories have demonstrated the first examples of DNA nanotubes with deliberately controlled geometry. Remarkable triangular and square-shaped tubes spontaneously form using these new techniques.

These nanotubes offer great potential, for example, for the construction of metal nanowires of different geometries. The DNA tube can be used as a mold into which metals are grown, creating microscopically thin wires that may have a wide variety of applications.

The team has also shown how these nanotubes can be created in an ‘open’, single-stranded form and ‘closed’ double-stranded form. These forms will be especially interesting for the encapsulation and selective release of drugs near the site of diseased cells.

Modular construction of DNA nanotubes of tunable geometry and single- or double-stranded character by Faisal A. Aldaye, Pik Kwan Lo, Pierre Karam, Christopher K. McLaughlin, Gonzalo Cosa & Hanadi F. Sleiman

Published online: 12 April 2009 | doi:10.1038/nnano.2009.72

DNA nanotubes can potentially act as stiff interconnects, tracks for molecular motors and nanoscale drug carriers. Researchers have now reported a modular approach to DNA nanotube synthesis that can create geometrically well-defined triangular and square tubes. The method allows parameters such as geometry, stiffness and single- or double-stranded character to be tuned, and could provide access to designer nanotubes for a range of applications.

19 pages of supplementary information on the work is here.