WEST LAFAYETTE, Ind. - Researchers working to advance imaging useful to medicine and security are capitalizing on the same phenomenon behind the lingering "ghost" image that appeared on old television screens.
A team of researchers from Purdue University and Macquarie University in Sydney has created a way to control the length of time light from a luminescent nanocrystal lingers, adding a new dimension of time to color and brightness in optical detection technology.
Detection based on the lifetime of the light as well as its specific color, or wavelength, exponentially boosts the number of different combinations that can be created and used as unique signatures, or tags, for biomedical screens. Screens based on this new technology could identify thousands of different target molecules simultaneously, far surpassing the current limits of such screens to roughly 20 different molecules.
"These nanocrystals can form combination codes, like barcodes, to form a vast library of distinguishable molecular probes, which can be used for complex diagnostics," said Dayong Jin, the professor of photonics at Macquarie who led the research. "They could be used for screening tests that can more quickly and accurately identify the cause of infection, residue cancers at an early stage and locate the specific molecular targets for targeted drug therapies."
In addition, light emitted by the new nanocrystals far outlasts that which occurs naturally in biological systems, called autofluorescence. That difference in timing distinctly separates the signal from background noise, said J. Paul Robinson, the professor of cytomics in Purdue's College of Veterinary Medicine and professor in Purdue's Weldon School of Biomedical Engineering who helped lead the study over the last four years.
"The photons emitted by these nanocrystals last 1,000 times longer than the photons emitted by biological systems that cause background noise," said Robinson, who also is director of
|Contact: Elizabeth Gardner|