title: DNA logic gate based on metallo-toehold strand displacement.
abstract: DNA is increasingly being used as an ideal material for the construction of nanoscale structures, circuits, and machines. Toehold-mediated DNA strand displacement reactions play a very important role in these enzyme-free constructions. In this study, the concept of metallo-toehold was utilized to further develop a mechanism for strand displacement driven by Ag+ ions, in which the intercalation of cytosine-cytosine mismatched base pairs on the toeholds provides additional control by varying of the concentration of Ag+ ions. The characteristics of displacement reaction in response to different concentration of Ag+ ions are investigated by fluorescence spectral and non-denaturing polyacrylamide gel electrophoresis. The reaction can successfully occur when the concentration of Ag+ ions is suitabe; excess Ag+ ions block the reaction. Furthermore, the displacement reaction can be tuned and controlled most efficiently under the condition of two C:C mismatched base pairs placed on the six-nt toehold. Based on our research, a mechanism was developed to construct Boolean logic gate AND and OR by employing strand displacement reaction as a tool, Ag+ and Hg2+ as input.
authors.affiliation: CAS Key Laboratory of Soft Matter Chemistry, Department of polymer science and engineering, University of Science and Technologyof China, Hefei, Anhui, P. R. China.
authors.forename: Wei
authors.initials: W
authors.lastname: Deng
authors.affiliation: CAS Key Laboratory of Soft Matter Chemistry, Department of polymer science and engineering, University of Science and Technologyof China, Hefei, Anhui, P. R. China.
authors.forename: Huaguo
authors.initials: H
authors.lastname: Xu
authors.affiliation: CAS Key Laboratory of Soft Matter Chemistry, Department of polymer science and engineering, University of Science and Technologyof China, Hefei, Anhui, P. R. China.
authors.forename: Wei
authors.initials: W
authors.lastname: Ding
authors.affiliation: CAS Key Laboratory of Soft Matter Chemistry, Department of polymer science and engineering, University of Science and Technologyof China, Hefei, Anhui, P. R. China; Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, P. R. China.
authors.forename: Haojun
authors.initials: H
authors.lastname: Liang
mesh_terms: D020137:Base Pair Mismatch; D004247:DNA / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D004261:DNA Replication; D007477:Ions / Q000737:chemistry; D011995:Recombination, Genetic; D012834:Silver / Q000737:chemistry
chemical_list: D007477:Ions; D012834:Silver; D004247:DNA