Luminescence Quenching by Photoinduced Charge Transfer between Metal Complexes in Peptide Nucleic Acids
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- 作者：Xing Yin ; Jing Kong ; Arnie De Leon ; Yongle Li ; Zhijie Ma ; Emil Wierzbinski ; Catalina Achim ; David H. Waldeck
- 刊名：Journal of Physical Chemistry B
- 出版年：2014
- 出版时间：July 31, 2014
- 年：2014
- 卷：118
- 期：30
- 页码：9037-9045
- 全文大小：445K
- ISSN：1520-5207
文摘
A new scaffold for studying photoinduced charge transfer has been constructed by connecting a [Ru(Bpy)3]2+ donor to a bis(8-hydroxyquinolinate)2 copper [CuQ2] acceptor through a peptide nucleic acid (PNA) bridge. The luminescence of the [Ru(Bpy)3]2+* donor is quenched by electron transfer to the [CuQ2] acceptor. Photoluminescence studies of these donor-bridge-acceptor systems reveal a dependence of the charge transfer on the length and sequence of the PNA bridge and on the position of the donor and acceptor in the PNA. In cases where the [Ru(Bpy)3]2+ can access the 蟺 base stack at the terminus of the duplex, the luminescence decay is described well by a single exponential; but if the donor is sterically hindered from accessing the 蟺 base stack of the PNA duplex, a distribution of luminescence lifetimes for the donor [Ru(Bpy)3]2+* is observed. Molecular dynamics simulations are used to explore the donor-PNA-acceptor structure and the resulting conformational distribution provides a possible explanation for the distribution of electron transfer rates.