TY  - JOUR
A1  - Choi, Youngeun
A1  - Kotthoff, Lisa
A1  - Olejko, Lydia
A1  - Resch-Genger, Ute
A1  - Bald, Ilko
T1  - DNA origami-based forster resonance energy-transfer Nanoarrays and their application as ratiometric sensors
JF  - ACS applied materials & interfaces
N2  - DNA origami nanostructures provide a platform where dye molecules can be arranged with nanoscale accuracy allowing to assemble multiple fluorophores without dye-dye aggregation. Aiming to develop a bright and sensitive ratiometric sensor system, we systematically studied the optical properties of nanoarrays of dyes built on DNA origami platforms using a DNA template that provides a high versatility of label choice at minimum cost. The dyes are arranged at distances, at which they efficiently interact by Forster resonance energy transfer (FRET). To optimize array brightness, the FRET efficiencies between the donor fluorescein (FAM) and the acceptor cyanine 3 were determined for different sizes of the array and for different arrangements of the dye molecules within the array. By utilizing nanoarrays providing optimum FRET efficiency and brightness, we subsequently designed a ratiometric pH nanosensor using coumarin 343 as a pH-inert FRET donor and FAM as a pH responsive acceptor. Our results indicate that the sensitivity of a ratiometric sensor can be improved simply by arranging the dyes into a well-defined array. The dyes used here can be easily replaced by other analyte-responsive dyes, demonstrating the huge potential of DNA nanotechnology for light harvesting, signal enhancement, and sensing schemes in life sciences.
KW  - DNA origami
KW  - nanoarray
KW  - FRET
KW  - ratiometric sensing
KW  - pH sensing
Y1  - 2018
U6  - https://doi.org/10.1021/acsami.8b03585
SN  - 1944-8244
SN  - 1944-8252
VL  - 10
IS  - 27
SP  - 23295
EP  - 23302
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Olejko, Lydia
A1  - Cywinski, Piotr J.
A1  - Bald, Ilko
T1  - Ion-Selective formation of a guanine quadruplex on DNA origami structures
JF  - Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition
N2  - 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.
KW  - DNA nanotechnology
KW  - FRET
KW  - G-quadruplexes
KW  - nanostructures
KW  - self-assembly
Y1  - 2015
U6  - https://doi.org/10.1002/anie.201409278
SN  - 1433-7851
SN  - 1521-3773
VL  - 54
IS  - 2
SP  - 673
EP  - 677
PB  - Wiley-VCH
CY  - Weinheim
ER  -