Programmed pH-Driven Reversible Association and Dissociation of Interconnected Circular DNA Dimer Nanostructures

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• 作者：Yuwei Hu ; Jiangtao Ren ; Chun-Hua Lu ; Itamar Willner
• 刊名：Nano Letters
• 出版年：2016
• 出版时间：July 13, 2016
• 年：2016
• 卷：16
• 期：7
• 页码：4590-4594
• 全文大小：391K
• 年卷期：0
• ISSN：1530-6992

文摘

The switchable pH-driven reversible assembly and dissociation of interlocked circular DNA dimers is presented. The circular DNA dimers are interconnected by pH-responsive nucleic acid bridges. In one configuration, the two-ring nanostructure is separated at pH = 5.0 to individual rings by reconfiguring the interlocking bridges into C–G·C⁺ triplex units, and the two-ring assembly is reformed at pH = 7.0. In the second configuration, the dimer of circular DNAs is bridged at pH = 7.0 by the T–A·T triplex bridging units that are separated at pH = 10.0, leading to the dissociation of the dimer to single circular DNA nanostructures. The two circular DNA units are also interconnected by two pH-responsive locks. The pH-programmed opening of the locks at pH = 5.0 or pH = 10.0 yields two isomeric dimer structures composed of two circular DNAs. The switchable reconfigured states of the circular DNA nanostructures are followed by time-dependent fluorescence changes of fluorophore/quencher labeled systems and by complementary gel electrophoresis experiments. The dimer circular DNA structures are further implemented as scaffolds for the assembly of Au nanoparticle dimers exhibiting controlled spatial separation.