Combinatorial Discovery of Lanthanide-Doped Nanocrystals with Spectrally Pure Upconverted Emission
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- 作者：Emory M. Chan ; Gang Han ; Joshua D. Goldberg ; Daniel J. Gargas ; Alexis D. Ostrowski ; P. James Schuck ; Bruce E. Cohen ; Delia J. Milliron
- 刊名：Nano Letters
- 出版年：2012
- 出版时间：July 11, 2012
- 年：2012
- 卷：12
- 期：7
- 页码：3839-3845
- 全文大小：389K
- 年卷期：v.12,no.7(July 11, 2012)
- ISSN：1530-6992
文摘
Nanoparticles doped with lanthanide ions exhibit stable and visible luminescence under near-infrared excitation via a process known as upconversion, enabling long-duration, low-background biological imaging. However, the complex, overlapping emission spectra of lanthanide ions can hinder the quantitative imaging of samples labeled with multiple upconverting probes. Here, we use combinatorial screening of multiply doped NaYF4 nanocrystals to identify a series of doubly and triply doped upconverting nanoparticles that exhibit narrow, spectrally pure emission spectra at various visible wavelengths. We then developed a comprehensive kinetic model validated by our extensive experimental data set. Applying this model, we elucidated the energy transfer mechanisms giving rise to spectrally pure emission. These mechanisms suggest design rules for electronic level structures that yield robust color tuning in lanthanide-doped upconverting nanoparticles. The resulting materials will be useful for background-free multicolor imaging and tracking of biological processes.