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Biomimicry "An artificial light-collecting antenna system. Binding a large number of light-absorbing molecules ('red balls') to a DNA molecule, which is then modified with a porphyrin unit (blue) will result in the creation of a self-assembling system that resembles light harvesting in natural photosynthesis."
Image Credit: Chalmers University of Technology

Published on June 24th, 2013 | by James Ayre

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Self-Assembling DNA Molecules As Scaffolding For Artificial Photosynthesis — Solar Energy Antenna Developed



An interesting new take on an artificial photosynthesis system — one relying on self-assembling DNA molecules for scaffolding rather than conventional materials — has just been developed by researchers at Chalmers University of Technology. The new system is composed of self-assembling DNA molecules mixed with simple dye molecules — creating an effective means of gathering sunlight to be used for artificial photosynthesis.

"An artificial light-collecting antenna system. Binding a large number of light-absorbing molecules ('red balls') to a DNA molecule, which is then modified with a porphyrin unit (blue) will result in the creation of a self-assembling system that resembles light harvesting in natural photosynthesis." Image Credit: Chalmers University of Technology

“An artificial light-collecting antenna system. Binding a large number of light-absorbing molecules (‘red balls’) to a DNA molecule, which is then modified with a porphyrin unit (blue) will result in the creation of a self-assembling system that resembles light harvesting in natural photosynthesis.”
Image Credit: Chalmers University of Technology

In most photosynthetic plants and algae, the ‘scaffolding’ consists of a large variety of proteins which work to organize chlorophyll molecules so as to maximize light collection. As you can probably guess, the system is rather complex, dynamic, and resilient — artificially constructing such a system would be at best an inefficient use of time, and at worst impossible.

“It’s all over if a bond breaks,” states Jonas Hannestad, PhD of physical chemistry. “If DNA is used instead to organise the light-collecting molecules, the same precision is not achieved but a dynamic self-constructing system arises.”

A self-assembling system with a capacity for self-repair? Sounds like a big improvement over current technology. “If any of the light-collecting molecules break, it will be replaced with another one a second later. In this sense, it is a self-repairing system as opposed to if molecules had been put there by researchers with synthetic organic chemistry.”



In photosynthetic plants and algae, the sunlight that hits them is redirected to a reaction center in which the energy of the sunlight can then be used to synthesize sugars and other molecules.

“We can move energy to a reaction center, but we have not resolved how the reactions themselves are to take place there,” says Bo Albinsson, professor of physical chemistry and head of the research team. “This is actually the most difficult part of artificial photosynthesis. We have demonstrated that an antenna can easily be built. We have recreated that part of the miracle.”

Chalmers University of Technology explains the technology:

When constructing nano-objects that are billionths of a meter, DNA molecules have proven to function very well as building material. This is because DNA strands have the ability to attach to each other in a predictable manner. As long as the correct assembly instructions are given from the start, DNA strands in a test tube can bend around each other and basically form any structure.

“It’s like a puzzle where the pieces only fit together in one specific way,” says Bo Albinsson. “That is why it is possible to draw a fairly complex structure on paper and then know basically what it will look like. We subsequently use those traits to control how light collection will take place.”

In related news, just a couple of months ago researchers unveiled an “artificial leaf” — promising “low-cost solar power for everybody.” It’s an interesting-looking technology, as is the artificial photosynthesis system described above. It’ll be interesting to see what happens with them both. Additionally, “solar antenna” stories have been popping out of universities and research institutes for years. This is by no means the first. Here are 4 CleanTechnica has covered over the years:

The new research was just published in the Journal of the American Chemical Society.

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About the Author

James Ayre's background is predominantly in geopolitics and history, but he has an obsessive interest in pretty much everything. After an early life spent in the Imperial Free City of Dortmund, James followed the river Ruhr to Cofbuokheim, where he attended the University of Astnide. And where he also briefly considered entering the coal mining business. He currently writes for a living, on a broad variety of subjects, ranging from science, to politics, to military history, to renewable energy. You can follow his work on Google+.



  • JamesWimberley

    Chalmers is a Swedish technical university, and a good one.

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