Biomedical Engineering Reference
In-Depth Information
Fig. 8.4
(
a
) Orientation-controllable assembly of gold nanorods on the surface of a triangular
DNA origami. (
b
) End-on and side-on combinations between a gold nanoparticle and a gold
nanorod assembled on a DNA origami (Reprinted with the permission from Ref. [
36
]. Copyright
2011 American Chemical Society)
To improve the encapsulation efficiency, three capture probes were displayed on
the inner surfaces of the origami cage, which could simultaneously hybridize with
the DNA strands on the gold nanoparticle. The authors then realized attachments
of other gold nanoparticles on selected outer facets of the DNA cage based on
sequence-specific DNA hybridizations (see Fig.
8.3
).
Orientation control of nonspherical nanomaterials is an important issue in
DNA-programmable nanoassembly, which is often true for one-dimensional nano-
materials such as carbon nanotubes and gold nanorods. Besides, another challenge
in DNA-directed self-assembly is how to attach a symmetric (spherical) nanoparticle
to a specific site on a low-symmetry nano-object as it is very hard to realize
a site-specific DNA decoration. Yan et al. showed that DNA origami could be
used to tackle the above challenges (Fig.
8.4
)[
36
]. They assembled a triangle-
shaped DNA origami and grew two lines of single-stranded DNA tags at a
predefined mutual orientation on the origami surface. Two DNA-decorated gold
nanorods recognized the complementary DNA glues on the origami and hybridized
with them to reach well-controlled inter-nanorod orientations of 0
ı
,60
ı
,90
ı
,
and 180
ı
. In another experiment, Yan et al. prepared a DNA monofunctional-
ized gold nanoparticle and mixed it with other staple stands to fold the M13
genome into a DNA triangle with the nanoparticle precisely located at its one
edge. Further attachment of a gold nanorod with both orientation and position
controls resulted in end-on and side-on nanoparticle-nanorod combinations on the
origami.
Search WWH ::
Custom Search