From Technology Review:

By adding fluorescent dyes to DNA and then spinning the DNA strands into nanofibers, researchers at the University of Connecticut have made a new material that emits bright white light. The material absorbs energy from ultraviolet light and gives off different colors of light–from blue to orange to white–depending on the proportions of dye it contains.

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The new material could be used to make a novel type of organic light bulb. The light emitters should also be longer-lasting because DNA is a very strong polymer, Sotzing says. “It’s well beyond other polymers [in strength],” he notes, adding that it lasts 50 times longer than acrylic.

The color-tunable DNA material relies on an energy-transfer mechanism between two different fluorescent dyes. The key is to keep the dye molecules separated at a distance of 2 to 10 nanometers from each other. When UV light is shined on the material, one dye absorbs the energy and produces blue light. If the other dye molecule is at the right distance, it will absorb part of that blue-light energy and emit orange light.

To make the fibers, Sotzing and his colleagues make a solution of salmon DNA and mix in the two types of dye. The solution is pumped slowly out from a fine needle, and a voltage is applied between the needle tip and a grounded copper plate covered with a glass slide. As the liquid jet comes out, it dries and forms long nanofibers that are deposited on the glass slide as a mat. The researchers then spin this nanofiber mat directly on the surface of an ultraviolet LED to make a white-light emitter.