Scientists use DNA as a nano-printing template

DNA is the most commonly used building block in nanotechnology and is often used to control the construction of ordered nanostructures. To a large extent, people think that DNA is expected to become the basic module for making microelectronic circuits from the bottom up.

Now, a group of scientists from Brigham Young University in the United States have combined DNA self-organizing technology with microfabrication to create structures such as nanochannels, nanowires, and nanochannels. This discovery opens up new paths for nanofabrication in sizes not available today with optical printing. Their results were published in the latest issue of Small.

Researchers Adam Woolley and Héctor Becerril developed a method for using DNA as a template to define a base pattern. They arranged the DNA on the substrate and deposited a metal film on it. DNA molecules act as nanowax papers, thus defining some patterns on the substrate that are smaller than 10 nanometers. Because metal films are deposited at a certain angle, the projection of DNA molecules to define the scale of the pattern on the substrate, so this method is called "DNA projection nanometer printing."

Afterwards, the researchers used an active gas plasma commonly used in the semiconductor industry to anisotropically etch the surface of the pattern to obtain high aspect ratio trenches on the substrate. These trenches can be sealed at the top to form a continuous nanochannel; or they can be chemically functionalized as templates for the deposition of metal nanowires. These template trenches and fabricated nanowires have a cross section of only 30 nanometers and can be cut to less than 10 nanometers. The exact size of the trench can be controlled by varying the deposition angle and deposition thickness.

The researchers believe that the use of surface-aligned DNA molecules can achieve complex pattern-to-substrate conversions. Wooley said: "This technology is characterized by the ability to use DNA to form patterns, and does not require DNA to maintain its nucleic acid structure." He believes that DNA projection nanoimprinting can be applied in the field of nanofluidic channels and chemical sensors.