The newest addition to the toolkit for using DNA as a nanotech building block is the ability to program the circumference of nanotubes made from DNA. From nanotechweb.org, written by Belle Dumé (requires free registration) “DNA tubes control their size“:
Being able to synthesize nanostructures with controlled size is an important goal in nanotechnology. Now, researchers in the US have succeeded in exploiting modular single-stranded DNA building blocks to create molecular tubes with predefined circumferences. Such tubes could eventually be used as templates to make nanowires with controlled electronic properties for future nanoelectronic devices.
“We describe a simple modular approach to programming molecular-tube circumferences,” team member Peng Yin of Caltech told nanotechweb.org. “Single-step annealing results in the self-assembly of long tubes displaying monodisperse circumferences of 4, 5, 6, 7, 8, 10 or 20 DNA helices.”
…Compared with previous research in controlling DNA tube circumferences, Yin and colleagues’ new process is substantially simpler. The researchers begin by self-assembling DNA tubes composed of parallel DNA helices from distinct short strand species, each measuring 42 bases. By pairing up the modular complementary domains within the strands, they create DNA lattices made up of parallel helices connected by single-stranded links. This design scheme means that only tubes of a certain circumference form from a set of initial DNA strands.
…DNA with programmable geometrical and mechanical properties might be used as building blocks for sophisticated architectures and devices — like tracks for molecular motors and as templates for organizing functional groups, for example.
The results, obtained in Erik Winfree’s lab at Caltech, were reported in Science [abstract].