Fluorescent Flashlights

Scientists have created the brightest ever synthesized fluorescent silica particles. These microscopic "flashlights" are 170 times brighter than any particles of similar size created so far. The previous record was reached with quantum dots.

The team led by Igor Sokolov, a physicist at Clarkson University, created the microscopic "flashlights" by entrapping a bunch of organic fluorescent molecules into a silica substance.

Molecules like these fluoresce when they get energized by an outside source of light. Then, the molecules re-emit the light at a different wavelength, or color.

The research, published in the March 5 issue of the journal Small, could have applications in medicine, forensic science and environmental protection. For instance, they could help track air pollution. "You could spray these particles into the air like dust," says Sokolov, "and easily collect them because they are so highly visible."

In addition, by using optical fibers, scientists could remove the "ignition" light, leaving behind only the fluorescence from the particles themselves. In that way, the tiny particles--less than a tenth the width of a human hair--could be used as sort of holograms imbedded in various objects to show authenticity. They could also be used like an "invisible ink" to prove that someone touched an object.

--LiveScience Staff

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Credit: Igor Sokolov