TY  - JOUR
A1  - Reinhardt, Matthias
A1  - Koc, Azize
A1  - Leitenberger, Wolfram
A1  - Gaal, Peter
A1  - Bargheer, Matias
T1  - Optimized spatial overlap in optical pump-X-ray probe experiments with high repetition rate using laser-induced surface distortions
JF  - Journal of synchrotron radiation
N2  - Ultrafast X-ray diffraction experiments require careful adjustment of the spatial overlap between the optical excitation and the X-ray probe pulse. This is especially challenging at high laser repetition rates. Sample distortions caused by the large heat load on the sample and the relatively low optical energy per pulse lead to only tiny signal changes. In consequence, this results in small footprints of the optical excitation on the sample, which turns the adjustment of the overlap difficult. Here a method for reliable overlap adjustment based on reciprocal space mapping of a laser excited thin film is presented.
KW  - ultrafast X-ray diffraction
KW  - nanostructures
KW  - surface deformation
KW  - heat diffusion
KW  - optical pump
Y1  - 2016
U6  - https://doi.org/10.1107/S1600577515024443
SN  - 1600-5775
VL  - 23
SP  - 474
EP  - 479
PB  - International Union of Crystallography
CY  - Chester
ER  - 
TY  - JOUR
A1  - Olejko, Lydia
A1  - Cywiński, Piotr J.
A1  - Bald, Ilko
T1  - An ion-controlled four-color fluorescent telomeric switch on DNA origami structures
JF  - Nanoscale
N2  - 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 Förster 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.
KW  - resonance energy-transfer
KW  - g-quadruplex
KW  - quantum dots
KW  - strand breakage
KW  - photonic wires
KW  - 3-color fret
KW  - nanostructures
KW  - recognition
KW  - sensitivity
KW  - assemblies
Y1  - 2016
U6  - https://doi.org/10.1039/C6NR00119J
SN  - 2040-3372
SN  - 2040-3364
VL  - 8
SP  - 10339
EP  - 10347
PB  - RSC Publ.
CY  - Cambridge
ER  -