Gold and DNA

Nanostructures made using DNA origami are fascinating. The ability to use DNA as a construction material, capable of holding scaffolds of molecules and atoms was one huge step in developing modern nanostrutures. Most recent of these developments are gold-plated nanowires constructed by scientists from the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and from Paderborn University, which independently assembled themselves from single DNA strands, as published in the journal Langmuir.

These nanowires, due to their gold-plating, were able to conduct electricity. "Our measurements have shown that an electrical current is conducted through these tiny wires," explains Artur Erbe of the Institute of Ion Beam Physics and Materials Research. The nano-sized structures were connected by two electrical contacts.

Even more fascinating is how these were made using modified DNA strands — stable double strands combined through their base pairs, from long single strands of genetic material and DNA segments. These allowed for the structures to independently take on their desired forms, complex structures developed by molecules through a self-assembling processes.

From the Bottom-Up

"With the help of this approach, which resembles the Japanese paper folding technique origami and is therefore referred to as DNA-origami, we can create tiny patterns. Extremely small circuits made of molecules and atoms are also conceivable here," says Erbe.

Usually, developing nano circuits use what is known as the "top-down" method, where the base material is chiseled until the desired structure is formed. This will become increasingly difficult as electronics continue miniaturization. The new "bottom-up" method changes how these electronic components are usually made.

Credits: B. Teschome, A. Erbe, et al.

There is one problem, though. "Genetic matter doesn't conduct a current particularly well," Erbe points out, which explains why the nanowires were gold-plated. But even with this, there was still difficulty with conducting current at room temperatures. Better melding of conductive materials need to be further developed, plus the option of using cheaper, more standard wire coating than gold.

Still, the research is promising. This nanowire that's made partially out of genetic material could be the future of electronics. Smaller wires allow for more compact designs, which together with smaller transistors, can be used to make more powerful computers.

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