Self-Assembled DNA-Inorganic Nanoparticle Structures - DNA Nanotechnology: From Structure to Function - page 189

origami was reported by Hung et al. [ 44 ]. They combined top-down lithography and
bottom-up DNA self-assembly approach to fabricate large-area, spatially ordered,
2-D arrays through precise binding of gold nanocrystals to each DNA origami and
site-selective deposition of DNA origami onto lithographically patterned substrates
(Fig. 9.5 d). This method opens up a door to the potential applications that the
origami may have in nanoscale electronics and photonics.
Besides AuNPs, other nanomaterials such as AgNPs, QDs, metal clusters, and
carbon nanotubes have also been used in DNA origami-directed assembly. Pal
et al. [ 12 ] succeeded in assembling AgNPs on a DNA origami scaffold. AgNPs
are more susceptible than AuNPs to oxidation and aggregation under high-salt
conditions, which are essential for the preparation of DNA nanostructures, they
solved this problem with the method as follows: AgNPs (20 nm in diameter)
were firstly functionalized with ps-po chimeric DNA strands 9ps-T15 that have
a segment of 9 bases with a phosphorothioate (9ps) backbone and a segment of
15 regular DNA bases linked with phosphodiester bonds (T15). The nine sulfur
atoms on the ps domain of the DNA backbone enable the DNA strand with high
affinity to the surface of the AgNPs. When the surface coverage with DNA was at
saturation level, the AgNPs showed stability against aggregation in solutions with
a high salt concentration. The other steps are almost the same as Ding's method
mentioned above (Fig. 9.6 a). Fluorescent sliver clusters(AgNCs) immobilized on
DNA origami were also achieved by Pal et al. [ 45 ]. They covalently incorporated
a small number of sugar moieties into a DNA sequence at adjacent positions and
hoped that they would enable the synthesis of AgNCs by the specific stoichiometry
Fig. 9.4 DNA motifs for NP self-assembly. ( a ) The tiling pattern used to assemble the 2-D DNA
crystals, DNA assembly shown at the right , the spacing between these features is 32 nm in
the horizontal direction and 4 nm in the vertical direction. The corresponding TEM image of a
DNA crystal incorporating the DNA-Au conjugate is at the below .( b ) Assembly steps for the
5-nm AuNP 2-D nanocomponent. The right is topographical AFM image and TEM image of the
assembled DNA-Au nanocomponents. ( c ) Assembly steps for the 5-nm and 10-nm AuNP 2-D
nanocomponent arrays. The right is corresponding AFM and TEM image of the two-particle array.
The pattern of alternating parallel rows of small and large gold particles is clearly visible. ( d )
Diagrams showing the attachment of nanoparticles. Its three panels show, top to bottom ,5-nm
particles attached to only one of the two triangular tiles , 5-nm particles attached to both of
the tiles, 5-nm particles attached to one of the tiles, and 10-nm particles attached to the other
tile. The TEM image shows the array where one tile contains a 5-nm particle and the other
tile contains a 10-nm particle. ( e ) Schematic representations of the DNA-templated assembly of
periodical AuNP nanoarrays. AFM images at below show the patterning of AuNPs on the self-
assembled DNA nanostructures. ( f ) Process of DNA-tile-directed self-assembly of QD arrays.
TEM and high-resolution TEM image at below show the periodic pattern of the organized QD
(Part ( a ) reprinted from Ref. [ 35 ] with kind permission from Springer Science C Business Media.
Part ( b ) reprinted with permission from Ref. [ 36 ]. Copyright 2004 American Chemical Society.
Part ( c ) reprinted with permission from Ref. [ 37 ]. Copyright 2005 American Chemical Society.
Part ( d ) reprinted with permission from Ref. [ 38 ]. Copyright 2006 American Chemical Society.
Part ( e ) reproduced from Ref. [ 40 ] with permission of John Wiley & Sons Ltd. Part ( f ) reproduced
from Ref. [ 41 ] with permission of John Wiley & Sons Ltd.)