UV Excitation of DNA Stabilized Ag Cluster Fluorescence via the DNA Bases
UV Excitation of DNA Stabilized Ag Cluster Fluorescence via the DNA Bases
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DOI：
10.1021/jp206110r
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发表时间：
2011-12-15
影响因子：
3.7
通讯作者：
Fygenson, Deborah Kuchnir
中科院分区：
文献类型：
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作者：
O'Neill, Patrick R.;Gwinn, Elisabeth G.;Fygenson, Deborah Kuchnir
我们报道了通过DNA碱基的UV激发作为DNA稳定的银簇荧光团（AgDNA）的可见发射的通用途径：在整个可见光谱中具有峰值发射的AgDNA在荧光激发中均呈现两个峰：在波长50 - 150 nm处的可见峰比发射峰短，并且取决于DNA链的具体特性，UV峰在260和270 nm之间。UV激发产生与可见光激发相同的发射光谱，根据具体的发射体，其强度大2 - 4倍。AgDNA的激发和吸收光谱之间的良好协议，AgDNA和裸DNA的吸收光谱之间的相似性，和无处不在的紫外线激发的所有研究的AgDNA强烈表明，紫外线激发收益通过DNA碱基，而不是通过直接激发更高的能量激发态的Ag簇。我们探讨的可能性，紫外线激发可以提供有关的类型，数量和方向的集群绑定基地。紫外激发作为一种有效的和通用的激发AgDNA荧光的手段，应被证明是有用的详细研究AgDNA分子物理学和鉴定和纯化最稳定的AgDNA荧光团。
We report UV excitation through the DNA bases as a universal pathway to visible emission from DNA stabilized silver cluster fluorophores (AgDNAs): AgDNAs with peak emissions throughout the visible spectrum all exhibit two peaks in fluorescence excitation: a visible peak at a wavelength 50-150 nm shorter than the emission peak and a UV peak between 260 and 270 nin depending on the specifics of the DNA Strand. UV excitation produces the same emission spectrum as visible excitation with 2-4 times greater intensity depending on the specific emitter. The excellent agreement between AgDNA excitation and absorption spectra, the similarity between AgDNA and bare DNA absorption spectra, and the ubiquity of UV excitation for all the AgDNAs studied strongly suggest that UV excitation proceeds via the DNA bases rather than by direct excitation of higher energy excited states of the Ag cluster. We explore the possibility that UV excitation can provide information about the type, number, and orientation of cluster-bound bases. As an efficient and universal means of exciting AgDNA fluorescence, UV excitation should prove useful in detailed studies of AgDNA photophysics and in identification and purification of the most stable AgDNA fluorophores.