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June 2012

Combinatorial Nanoscience Shines in Pure Colors

Green/red purity vs. total intensity, observed in the various lanthanide ion combinations.

The Molecular Foundry's Delia Milliron and colleagues have employed a powerful combinatorial approach to synthesize nanocrystals that glow in bright, pure colors when excited with near infrared light. – a process known as upconversion. These nanocrystals may allow for biological imaging with less harmful radiation than current methods, and can be more easily tracked and quantified due to their single color emission.

Milliron's team used a wide-sweeping approach to identify promising lanthanide ion combinations, using the automatic synthesis robot, WANDA, able to perform 96 different reactions in parallel. Ultimately four combinations of different ions were identified which responded to IR radiation by emission of pure red and pure green light.  

The wealth of data acquired from the roughly 300 reactions performed was then used to develop a theoretical model which accurately predicts the color and purity of the upconverted light emitted by any combinations of ions. 

"Combinatorial Discovery of Lanthanide-Doped Nanocrystals with Spectrally Pure Upconverted Emission" Emory M. Chan*, Gang Han, Joshua D. Goldberg, Daniel J. Gargas, Alexis D. Ostrowski, P. James Schuck, Bruce E. Cohen, and Delia J. Milliron*
The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States Nano Lett., Article ASAP
DOI: 10.1021/nl3017994 Publication Date (Web): June 19, 2012 Copyright © 2012 American Chemical Society
This work was carried out entirely at the Molecular Foundry and was supported by the Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.