DNA-Directed Assembly of Nanophase Materials: An Updated Review - DNA Nanotechnology: From Structure to Function - page 161

Fig. 8.5 Helical assembly of gold nanoparticles around a 24-helix bundle made by DNA origami,
resulting in left- and right-handed nanoparticle helices with chiral plasmonic optics (Reprinted by
permission from Macmillan Publishers Ltd: Ref. [ 37 ], copyright 2012)

8.3.3 DNA-Programmable Chiral Assemblies

of Plasmonic Nanomaterials

Previous research has demonstrated that gold nanoparticles could be organized
by DNA to form a chiral structure with tetrahedral or helical arrangement of
the nanoparticles [ 25 - 27 ]. Very recently, Kuzyk et al. achieved optically active
metamaterials formed by nine equally spaced gold nanoparticles arranged in right-
and left-handed helical fashions around a rodlike DNA origami (Fig. 8.5 )[ 37 ].
The DNA template was a 24-helix bundle that offered nine helically arranged
attachment (hybridization) sites for the gold nanoparticles (10 nm diameter). The
most exciting result achieved in this work was that, in agreement with theoretical
predictions, the helical nanoparticle assemblies clearly exhibited circular dichroism
with optical rotatory dispersion effects at visible wavelengths. This work provided
a rational strategy to design and fabricate a chiral nanostructure with easily tunable
handedness.