DNA molecules programmed to self-assemble into patterned nanostructures
September 26, 2003 | Source: KurzweilAI
Duke University researchers have used self-assembling DNA molecules as molecular building blocks called “tiles” that could lead to programmable construction of nanoscale protein-bearing scaffolds and metallized wires for nanoelectronics devices.
Because DNA strands naturally but selectively stick together, the Duke team reported that they could make the strands arrange themselves into cross shaped “tiles” capable of forming molecular bonds on all four ends of the cross arms. As a result, large numbers of the crosses could naturally stick together to form semi-rigid waffle-patterned arrays that the researchers called “stable and well behaved.”
Two types of DNA bases selectively pair up with the two others to form DNA strands — adenine with thymine and guanine with cytosine — so the scientists could exploit those biochemical properties to program different ways for their tiles to link together.
When the tiles were programmed to link with their faces all oriented in the same up or down direction, they self-assembled into narrow and long waffled “nanoribbons.” But when each tile’s face was programmed to point in the opposite direction from its neighbor, wider and broader waffled “nanogrids” were formed.
A two-step metallization procedure allowed the 4 x 4 nanoribbons to act as a scaffold for the production of highly conductive, uniform-width, silver nanowires.
“The big promise is that if we can increase the size of our lattices we can template nanoelectronics onto them and make useful devices and circuits at a smaller scale than has ever been done before,” said Thom LaBean, a molecular biologist and Duke University assistant research professor of computer science.