@article{OlejkoCywinskiBald2015,
  author    = {Olejko, Lydia and Cywinski, Piotr J. and Bald, Ilko},
  title     = {Ion-Selective formation of a guanine quadruplex on DNA origami structures},
  series = {Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition},
  volume    = {54},
  journal   = {Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition},
  number    = {2},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1433-7851},
  doi       = {10.1002/anie.201409278},
  pages     = {673 -- 677},
  year      = {2015},
  abstract  = {DNA origami nanostructures are a versatile tool that can be used to arrange functionalities with high local control to study molecular processes at a single-molecule level. Here, we demonstrate that DNA origami substrates can be used to suppress the formation of specific guanine (G) quadruplex structures from telomeric DNA. The folding of telomeres into G-quadruplex structures in the presence of monovalent cations (e.g. Na+ and K+) is currently used for the detection of K+ ions, however, with insufficient selectivity towards Na+. By means of FRET between two suitable dyes attached to the 3- and 5-ends of telomeric DNA we demonstrate that the formation of G-quadruplexes on DNA origami templates in the presence of sodium ions is suppressed due to steric hindrance. Hence, telomeric DNA attached to DNA origami structures represents a highly sensitive and selective detection tool for potassium ions even in the presence of high concentrations of sodium ions.},
  language  = {en}
}
@article{OlejkoCywińskiBald2016,
  author    = {Olejko, Lydia and Cywiński, Piotr J. and Bald, Ilko},
  title     = {An ion-controlled four-color fluorescent telomeric switch on DNA origami structures},
  series = {Nanoscale},
  volume    = {8},
  journal   = {Nanoscale},
  publisher = {RSC Publ.},
  address   = {Cambridge},
  issn      = {2040-3372},
  doi       = {10.1039/C6NR00119J},
  pages     = {10339 -- 10347},
  year      = {2016},
  abstract  = {The folding of single-stranded telomeric DNA into guanine (G) quadruplexes is a conformational change that plays a major role in sensing and drug targeting. The telomeric DNA can be placed on DNA origami nanostructures to make the folding process extremely selective for K+ ions even in the presence of high Na+ concentrations. Here, we demonstrate that the K+-selective G-quadruplex formation is reversible when using a cryptand to remove K+ from the G-quadruplex. We present a full characterization of the reversible switching between single-stranded telomeric DNA and G-quadruplex structures using F{\"o}rster resonance energy transfer (FRET) between the dyes fluorescein (FAM) and cyanine3 (Cy3). When attached to the DNA origami platform, the G-quadruplex switch can be incorporated into more complex photonic networks, which is demonstrated for a three-color and a four-color FRET cascade from FAM over Cy3 and Cy5 to IRDye700 with G-quadruplex-Cy3 acting as a switchable transmitter.},
  language  = {en}
}