Scientists grow solar cell components in tobacco plants

January 29, 2010 by Lisa Zyga, report
Scientists are working on synthesizing solar cells from chromophore structures they produced in tobacco plants. Image credit: US Department of Agriculture.

( -- Over billions of years, plants have evolved very efficient sunlight-collecting systems. Now, scientists are trying to harness the finely tuned systems in tobacco plants in order to use them as the building blocks of solar cells. Scientists predict that the technique could lead to the production of inexpensive, biodegradable solar cells.

In a recent study, scientists from UC Berkeley led by Matt Francis have demonstrated how to program tobacco plants to take advantage of the efficient way that they collect . Rather than attempt to reprogram all the cells of a mature tobacco plant, the scientists genetically engineered a virus called the tobacco mosaic virus to do the job for them. The researchers sprayed the modified virus on a crop of tobacco plants, and the virus caused the plant cells to produce lots of artificial chromophores, which turn photons from sunlight into electrons.

In order for the chromophores to work, however, they must be spaced at a precise distance from one another - about two or three nanometers. A little closer or further apart, and the will either be halted or the will be very difficult to harvest.

Thankfully, tobacco plant cells have evolved to space chromophores at this exact distance, lining them up in a long spiral hundreds of nanometers long. By exploiting this structure, the researchers could take advantage of billions of years of evolution to grow perfectly spaced strands of chromophores.

"Over billions of years, evolution has established exactly the right distances between to allow them to collect and use light from the sun with unparalleled efficiency," said Francis.

Since the modified themselves don’t generate electricity, the researchers must harvest the plants and extract the chromophore structures. Then, the scientists can dissolve the structures in a liquid solution, and then spray the solution on a glass or plastic substrate to create a solar cell. So far, the scientists have not yet demonstrated that the resulting can turn light into electrical energy.

Compared with traditional solar cells, those made from plants could have several potential advantages. For instance, they don’t require the use of toxic chemicals, they’re biodegradable, and they’re inexpensive to produce. On the other hand, bio-based solar cells would likely have a shorter lifetime than silicon solar cells.

In addition to using tobacco, the researchers also demonstrated how to manipulate E. coli bacteria to produce chromophore structures. In this case, the researchers didn’t use a virus, but modified the bacteria directly.

Explore further: Scientists grow insulin in tobacco plants

More information: Michel T. Dedeo, Karl E. Duderstadt, James M. Berger and Matthew B. Francis. “Nanoscale Protein Assemblies from a Circular Permutant of the Tobacco Mosaic Virus.” Nano Lett., 2010, 10 (1), pp 181-186. doi:10.1021/nl9032395

Via: Discovery News

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5 / 5 (3) Jan 29, 2010
Very encouraging to see scientists trying to tap into billion year old algorithms.
5 / 5 (2) Jan 29, 2010
Maybe tobacco farming can make a comeback and be the high tech crop of the future.
5 / 5 (3) Jan 29, 2010
perhaps using a pot plant my yield better results
not rated yet Jan 29, 2010
"Over billions of years, evolution has established exactly the right distances between chromophores to allow them to collect and use light from the sun with unparalleled efficiency," said Francis.

The only problem is that the typical efficiency of plants is terrible, on the order of 3%.
5 / 5 (1) Jan 30, 2010
Yes. The thing to remember is that plants (or anything else for that matter) does not evolve towards being as efficient as possible but only evolves toward being just efficient _enough_ to outcompete its competitors.
5 / 5 (1) Jan 30, 2010
I seriously doubt land-based plants have even existed for "billions" of years.
1 / 5 (2) Jan 30, 2010
I have almost finshed writing a opatent on using recombinant tobacco plants to manufacture gene therapy vectors. "green therapy"
2.5 / 5 (2) Jan 30, 2010
"Over billions of years, evolution has established exactly the right distances between chromophores to allow them to collect and use light from the sun with unparalleled efficiency," said Francis.

The only problem is that the typical efficiency of plants is terrible, on the order of 3%.

The consensu among soalr enrgy experst is that artifical solar cells will overtake plants in all measures of efficiency and econmic viability. Covering small patches of the desrt with solar cells, a 10 mile X 10 mile solar farm could supply the entire United States Enrrgy requirements. Of course there is no way that all that electircity can be used to move trucks unless battery power becomes practical.
1 / 5 (5) Jan 31, 2010
What proof do these "Experts" have of any kind of evolution? How the plants came to have the chromophores, or whatever trait for collecting solar energy, is a totally unrelated topic. They just left science and now are preaching their religious beliefs concerning origins. If these plants took billions of years to get the process right, show me a "missing link". In the beginning God created the heavens and the earth. Do you know what the word "Universe" means? "Single-spoken-word". Yes, God spoke everything into existance!
He also made plants and animals, and the world we live in, just like it says in the book of Genesis.
It is great when we discover God provided things, such as in these plants, which may provide energy for us. Best wishes to new discoveries, but keep your false religions to yourself.
not rated yet Jan 31, 2010

get ur unscience rubbish off this website. if u cant handle that evolution is a fact (ie has been observed in nature) and is a beuatiful theory which has withstood 150 years of testing, and has only become stronger (especially since the discovery of DNA and genomes began being sequence), then get off this site and keep ur religious rubbish to urself. scientists are about discovering things about the real world, ur religious trash just halts progress.
not rated yet Feb 01, 2010
Zander; You say evolution is a fact - without any scientific proof to back it, and you also say it is a theory. You should be more certain about defending your evolution religion. 150 years since what? Messiah Darwin? He wasn't the first to come up with the rediculous theory of evolution. But, there were many scientists throughout the ages who were believers in creation, do some research before becoming emotional and making yourself look foolish.
not rated yet Feb 02, 2010
...but keep your false religions to yourself.

Hah.. this in light of all that you've professed.
If it is merely theory, which somehow diminishes it's credence in your eyes, then you might as well stop taking antibiotics, eating domesticated meat and crops, and caring for domesticated animals since these are clearly abominations.
The difference between is that one is testable, and the other explicitly relies on FAITH.
What's even more ludicrous is how you said "...without any scientific proof to back it..." which just throws ages of research and results out of the window.
You honestly shouldn't be commenting since you quite apparently don't understand the subject material and reject established foundations in favor of your own very personal convictions.
Nonetheless, you should definitely be reading the material here - lord knows you need it.
not rated yet Feb 02, 2010
LOL. How do you test evolution? You have a camera and a time machine? A theory has to be proven to become fact. I don't understand your connection to antibiotics etc. Louis Pasteur was a Christian man and we can all appreciate his work as a scientist.
You are correct in saying evolution requires faith. So much so, that I don't have enough faith to be an atheist, which most evolutionists really are. I understand quite well that evolutionists really just don't want to accept that there is a God. I have personal convictions just like you, just like everyone. Does that disqualify me? There is not one shread of incontestable proof for evolution. I ask you to give me even just one example.
5 / 5 (2) Feb 02, 2010
First: Saying it's a theory doesn't mean there isn't proof for it. Gravity is still a theory, all we can do is make repeated tests to try to disprove our theories. When they are not disproven, the theory is strengthened.

Second: Everyone please realize that this is almost certainly a troll. Even if it isn't, 99% of the readers here believe in evolution, and the others will not be convinced by reading comments on the internet.

Third: While this looks really cool, I doubt it will be a major step in the solar energy industry. Hopefully I'll be proven wrong about that.
5 / 5 (1) Feb 03, 2010
Second: Everyone please realize that this is almost certainly a troll. Even if it isn't, 99% of the readers here believe in evolution, and the others will not be convinced by reading comments on the internet.

not rated yet Feb 03, 2010
I figured as much, you offer no proof. Now you say I am off topic. Numbers of people who agree, will not make something right or wrong. Taking comfort in such numbers is only a false sense of security for you. My questions still stand.
not rated yet Feb 04, 2010
Anyone who doesn't think Evolution is an obvious fact is a dunderhead who is too thick to run a simple 'survival of the fittest' scenario in their heads.
Think about it: Animal DNA chaotically mutates every generation. Most mutations do nothing and have negligible effect. Some mutations, however, are genuinely beneficial to aid survival in their particular environments. Such animals which are more apt to survive are more apt to breed and pass on aforementioned mutations. This buildup of mutations causes animals to 'adapt' to their environments as generations proceed.

This makes perfect sense to almost all people, if it doesn't to you you may want to wonder why.
not rated yet Feb 06, 2010
Please do the some research into evolution and maybe read a few books and you will then find the proof that everyone else thinks is credible. More credible then the word of "god" written by men with their own perspective. I'd ask you for proof but really its hardly at all substantial!

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