This is much more than just a pretty picture. Scientists have “repainted” Vincent van Gogh’s “Starry Night” using folded DNA molecules, and it could have some surprising benefits for computer science.
The “DNA origami” technique is outlined in this study published in Nature. It’s been 10 years since that paper and the techniques have understandably come a long way. Their shapes started as small smiley faces and other simple patterns. But now they’ve refined the process so much they can recreate a masterpiece landscape less than 17 millimeters (0.7 inches) wide.
It’s all created by folding and refolding a single long strand of viral DNA into tiny single shapes.They use short strands of DNA like a staple to hold the overall shapes in place. This process can create structures that are under 100 nanometers in diameter. However, creating an intended shape is easier said than done.
As Paul Rothemund, a Research Professor at Caltech, explained in a statement: “If you just pour DNA origami over a surface to which they stick, they attach everywhere. It's a little like taking a deck of playing cards and throwing it on the floor; they are scattered willy-nilly all over the place. Such random arrangements of DNA origami are not very useful. If they carry electronic circuits, for example, they are difficult to find and wire up into larger circuits."
So, the researchers used electron-beam lithography and oxygen plasma etching onto templates that outlined the desired shape. The origami nanostructure is all held down to the template using positively charged magnesium ions, which stick to both the DNA structure and the negatively charged etched patches on the template. This means when the DNA solution is poured onto the template in sticks to where has been etched.
In the case of Ashwin Gopinath's "Starry Night" rendition, it also demonstrates the first-known application of DNA origami to place fluorescent molecules into microscopic light sources, giving it that shaded red glow. It relies on photonic crystal cavities (PCC), microscopic structures that resonate at a particular wavelength of light. Depending on the size and spacing of the holes, it changes the “shades”. The ability of the DNA origami to place these PCC further shows the ability of this technique to master the macroscopic world.
It may seem like a bit of fun but there are some serious implications behind it. The researchers behind this unlikely marriage between biochemistry, computers, and art are hoping their work will one day contribute to the development of smaller and faster computers. The Caltech researchers have been collaborating with IBM since 2009. The DNA origami structures have the potential to help us understand how we can construct nanotechnology out of molecules.
As Rothemund went on to explain: “The spacing between the components can be 6 nanometers, so the resolution of the process is roughly 10 times higher than the process we currently use to make computer chips."
He added: "Then, if you want to design a really small electronic device, say, you just design DNA strands to create the pattern you want, attach little chemical 'fastening posts' to those DNA strands, assemble the pattern, and then assemble the components onto the pattern."
Smiley faces that are 100 nanometers across (1/1000th the width of a human hair). Image credit: Paul Rothemund/Caltech. Rendered by Nick Papadakis
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