NEW YORK, Oct. 8 - A novel way to initiate and control chemical reactions on DNA strands may lead to new DNA-based sensors and gene-therapy procedures, according to scientists at the US Department of Energy.
Researchers at Argonne National Laboratory said the new technology is based on their discovery of small organic molecules that connect the electronic properties of semiconductors to biological or organic molecules. They used the molecules, which they call conductive linkers, to connect strands of DNA to titanium dioxide crystals 4.5 nanometers wide.
Since a titanium dioxide nanocrystal in the presence of light acts as a semiconductor and can generate "strong oxidizing power" that attacks organic molecules, the team said that that by using different conductive linkers they can "selectively control oxidation."
This can come in handy in DNA-based sensing devices, the researchers assert. For example, the scientists determine the sequence and structure of DNA strands by measuring the speed of electron transfers. Here's how it would work: Each DNA base has a different electronic property that varies with the sequence and structure of that DNA strand. By activating the titanium dioxide with light, the team can study the reactions and determine the sequence by comparing the speed and efficiency of the reactions.
The team is part of the Argonne Chemistry Division and includes Chemistry Division Director Marion Thurnauer and chemists Tijana Rajh, David Tiede and Lin Chen. In addition, the team has collaborated with Gayle Woloshak of Northwestern University, formerly of Argonne, to exploit this chemistry for use in gene therapy.