DNA light bulb
Scientists have built an unusual LED using the "molecule of life" as a key component. Gregory Sotzing and his colleagues from the University of Connecticut reported on the appearance of a new light source.
The researchers added a set of two types of fluorescent dyes to the salmon DNA molecules, which themselves attached to the spiral. Then physicists spun nanoscale fibers from a set of DNA using the so-called electrospinning.
The resulting material had a highly organized structure with a homogeneous distribution of chromophores, and this was important for the final product.
Gregory and members of his laboratory placed such DNA fibers on the surface of an ultraviolet LED. When the latter was turned on, the new coating effectively converted ultraviolet into visible light, the spectrum of which depended on the proportions between the two types of dyes.
By changing the mass fraction of the dye, the authors of the invention report, it is possible to change the color temperature of white (from cold to warm shade), and when changing the proportions of fluorescent DNA molecules, the light bulb can produce almost any color stream, from blue to orange.
At the same time, for fine-tuning the spectrum, it turned out to be very important that the dyes were not just in a certain ratio to each other, because in this case they could simply be mixed "in a flask", without any DNA. The secret of the new system is that the chromophore molecules of various types are located here at a precisely adjusted distance from each other (this is what the DNA helix provides), as a result of which conditions are created for multiple re-emission of the initial waves from the UV LED at new frequencies and the addition of such secondary waves among themselves.
Interestingly, earlier the same researchers tried to simply place a thin film of DNA molecules with dyes connected to the biopolymer on the surface of an ultraviolet LED. But experience has shown that a system based not just on DNA, but on fibers woven from "molecules of life" gives 10 times brighter light. And the whole point is in a more effective transfer of energy between chromophore molecules.
American experimenters note that DNA is a strong and durable polymer, so that new organic LEDs can work longer than other rivals. The details of this work are set out in an article in Angewandte Chemie.
Portal "Eternal youth" http://vechnayamolodost.ru23.07.2009