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"Light Show" -- The Discovery Files

The Discovery Files
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Engineers at Ohio State University have invented a new kind of nano-particle that shines in different colors to tag molecules in biomedical tests.

Credit: NSF/Karson Productions

Audio Transcript:

Dot Matrix.

I'm Bob Karson with the discovery files -- new advances in science and engineering from the National Science Foundation.

See dot go. No, it's not a page from the old Dick and Jane readers but a look at a new kind of nano-particle that can be used to tag and track molecules.

Engineers at Ohio State University have developed the particles, which glow brightly in red, green or yellow because inside are ultra-tiny pieces of semiconductor called quantum dots. Like little traffic lights, they blink in color.

Let's say you are studying a disease like cancer. We already have ways to follow molecules by tagging them with a fluorescent material. But the colored quantum dots glow much brighter -- they're easier to see. And the different colors help keep track of individual molecules that otherwise might get lost in the shuffle during a complex biological process. The colors allow researchers to see the inner workings of individual living cells.

Because of quantum mechanical effects, the dots twinkle on and off at random moments. But by packaging a few different colored dots together inside a nano-sized container, the blinking becomes a steady glow, allowing for continuous tracking.

By shedding light on biological processes at the molecular or cellular level, the nanoparticles could be a valuable tool in the search for the roots of major diseases. Connecting the dots, for one very exciting light show.

"The Discovery Files" covers projects funded by the government's National Science Foundation. Federally sponsored research -- brought to you, by you! Learn more at or on our podcast.

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