TECHNOLOGY NEWS - NANOTECHNOLOGY
DNA strands could act as wires in biologically based electronics and medical devices. Researchers at Ohio State University (Columbus, OH, USA) have invented a process for uncoiling long strands of DNA and forming them into precisely patterned shapes.
In an online edition of the Proceedings of the National Academy of Sciences (www.pnas.org), L. James Lee, professor of chemical and biomolecular engineering, and postdoctoral researcher Jingjiao Guan describe the process.
Other labs have formed very simple structures with DNA that are now used in devices for gene testing and medical diagnostics. Lee and Guan are the first to coax strands of DNA into ordered, complex structures that resemble stitches on a quilt. The longest strands are 1 mm long and 1 nm thick. “These are very narrow, very long wires that can be designed into patterns for molecular electronics or biosensors,” says Lee. “In our case, we want to try to build tools for gene delivery, DNA recombination, and maybe even gene repair.”
In the patent-pending technology, the researchers press a tiny rubber comb into a drop of water containing coils of DNA molecules. Some of the DNA strands fall between the comb’s teeth, so that the strands uncoil and stretch out along the surface of the comb as it is pulled from the water. The comb is then placed on a glass chip surface. Depending on how the comb is placed, it leaves behind strands of different lengths and shapes. “Basically, we’re doing nanotechnology using a piece of rubber and a tiny droplet of DNA solution,” Guan says.
Bioelectronic computer chips could make it easier to diagnose disease and detect certain chemicals. To that end, researchers must first develop technologies to mass-produce DNA circuits.
The university will licence the technology for further development. Lee and Guan are working on building the wires into sensors for detecting disease biomarkers. The researchers are collaborating with the Department of Electrical and Computer Engineering at the university to measure the electrical properties of the DNA wires. The technique is also being used to produce DNA-based nanoparticles for gene delivery.
