Spectral Properties of Individual DNA-Hosted Silver Nanoclusters at Low Temperatures

详细信息    查看全文

• 作者：Sumant S. R. Oemrawsingh ; Nemanja Marke拧evi膰 ; Elisabeth G. Gwinn ; Eric R. Eliel ; Dirk Bouwmeester
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：December 6, 2012
• 年：2012
• 卷：116
• 期：48
• 页码：25568-25575
• 全文大小：402K
• 年卷期：v.116,no.48(December 6, 2012)
• ISSN：1932-7455

文摘

We report on the first single emitter fluorescence spectra of DNA-stabilized silver clusters (Ag:DNAs) at ambient and cryogenic temperatures. While Ag:DNAs have received much attention recently due to their sequence-tunable emission wavelengths, the nature of the optical transitions (molecule-like or collective, cluster-like) is an open question. By removing the ensemble broadening present in previous spectroscopic studies, we probe the line widths 螕 and brightness of individual Ag:DNA emitters. A roughly 5-fold increase in brightness from 295 to 1.7 K is accompanied by a factor of 2 decrease in 螕. The symmetric emission line shape, its insensitivity to embedding medium, and the independence of emission wavelength on excitation energy together indicate that the measured 螕 represents the homogeneous line width, while the large, 100 meV values of 螕 suggest rapid dephasing of a collective excited state of the silver cluster.