5 research outputs found
Voltage-Dependent Properties of DNA Origami Nanopores
We show DNA origami nanopores that
respond to high voltages by
a change in conformation on glass nanocapillaries. Our DNA origami
nanopores are voltage sensitive as two distinct states are found as
a function of the applied voltage. We suggest that the origin of these
states is a mechanical distortion of the DNA origami. A simple model
predicts the voltage dependence of the structural change. We show
that our responsive DNA origami nanopores can be used to lower the
frequency of DNA translocation by 1 order of magnitude
Proximity-Induced H‑Aggregation of Cyanine Dyes on DNA-Duplexes
A wide variety of organic dyes form,
under certain conditions,
clusters know as J- and H-aggregates. Cyanine dyes are such a class
of molecules where the spatial proximity of several dyes leads to
overlapping electron orbitals and thus to the creation of a new energy
landscape compared to that of the individual units. In this work,
we create artificial H-aggregates of exactly two Cyanine 3 (Cy3) dyes
by covalently linking them to a DNA molecule with controlled subnanometer
distances. The absorption spectra of these coupled systems exhibit
a blue-shifted peak, whose intensity varies depending on the distance
between the dyes and the rigidity of the DNA template. Simulated vibrational
resolved spectra, based on molecular orbital theory, excellently reproduce
the experimentally observed features. Circular dichroism spectroscopy
additionally reveals distinct signals, which indicates a chiral arrangement
of the dye molecules. Molecular dynamic simulations of a Cy3–Cy3
construct including a 14-base pair DNA sequence verified chiral stacking
of the dye molecules
Proximity-Induced H‑Aggregation of Cyanine Dyes on DNA-Duplexes
A wide variety of organic dyes form,
under certain conditions,
clusters know as J- and H-aggregates. Cyanine dyes are such a class
of molecules where the spatial proximity of several dyes leads to
overlapping electron orbitals and thus to the creation of a new energy
landscape compared to that of the individual units. In this work,
we create artificial H-aggregates of exactly two Cyanine 3 (Cy3) dyes
by covalently linking them to a DNA molecule with controlled subnanometer
distances. The absorption spectra of these coupled systems exhibit
a blue-shifted peak, whose intensity varies depending on the distance
between the dyes and the rigidity of the DNA template. Simulated vibrational
resolved spectra, based on molecular orbital theory, excellently reproduce
the experimentally observed features. Circular dichroism spectroscopy
additionally reveals distinct signals, which indicates a chiral arrangement
of the dye molecules. Molecular dynamic simulations of a Cy3–Cy3
construct including a 14-base pair DNA sequence verified chiral stacking
of the dye molecules
Proximity-Induced H‑Aggregation of Cyanine Dyes on DNA-Duplexes
A wide variety of organic dyes form,
under certain conditions,
clusters know as J- and H-aggregates. Cyanine dyes are such a class
of molecules where the spatial proximity of several dyes leads to
overlapping electron orbitals and thus to the creation of a new energy
landscape compared to that of the individual units. In this work,
we create artificial H-aggregates of exactly two Cyanine 3 (Cy3) dyes
by covalently linking them to a DNA molecule with controlled subnanometer
distances. The absorption spectra of these coupled systems exhibit
a blue-shifted peak, whose intensity varies depending on the distance
between the dyes and the rigidity of the DNA template. Simulated vibrational
resolved spectra, based on molecular orbital theory, excellently reproduce
the experimentally observed features. Circular dichroism spectroscopy
additionally reveals distinct signals, which indicates a chiral arrangement
of the dye molecules. Molecular dynamic simulations of a Cy3–Cy3
construct including a 14-base pair DNA sequence verified chiral stacking
of the dye molecules
Gap-Dependent Coupling of Ag–Au Nanoparticle Heterodimers Using DNA Origami-Based Self-Assembly
We
fabricate heterocomponent dimers built from a single 40 nm gold
and a single 40 nm silver nanoparticle separated by sub-5 nm gaps.
Successful assembly mediated by a specialized DNA origami platform
is verified by scanning electron microscopy and energy-dispersive
X-ray characterization. Dark-field optical scattering on individual
dimers is consistent with computational simulations. Direct plasmonic
coupling between each nanoparticle is observed in both experiment
and theory only for these small gap sizes, as it requires the silver
dipolar mode energy to drop below the energy of the gold interband
transitions. A new interparticle-spacing-dependent coupling model
for heterodimers is thus required. Such Janus-like nanoparticle constructs
available from DNA-mediated assembly provide an effective tool for
controlling symmetry breaking in collective plasmon modes