10 Realization of Artificial Chirality in Micro-/Nano-Scale …
257
Fig. 10.11 3D chiral nanostructures synthesized by DNA self-assembly. a Schematics and TEM
images of a tetramer of four gold NPs assembled by double-stranded DNA. b An assemble of gold
NPs positioned by using a DNA origami bundle [59] and c its circular dichroism (top: measured,
bottom: simulated) [59]. d Four gold NPs bound in a chiral arrangement by using a DNA origami
sheet [71] and e measured circular dichroism [71]. f Twisted layer of gold nanorods stacked by using
origami sheets [65]. g Schematics of a reconfigurable 3D chiral nanostructure [72]. h Schematics
of dynamic reconfiguration. The nanorods can be switched between a tightly folded state and an
extended state, and between two folded states with opposite handedness. (a) from [67], (b) and
(c) from [59], (d) and (e) from [71], (f) from [73], (g) from [72], (h) from [74]
dressed nanospheres. 3D chiral nanostructures have been also made with a small
number of nanospheres in a tetramer arrangement [71]; to realize a chiral geometry, four binding sites were defined on a rectangular DNA origami template, i.e.,
three on the top surface and one on the bottom surface (Fig. 10.11d). The position of the binding sites on the bottom surface breaks the mirror symmetry and
determines the handedness. Four gold NPs were functionalized using complementary DNA strands and positioned, then one was positioned at each binding site by
exploiting DNA hybridization. The fabricated structure showed CD in the visible
spectrum (Fig. 10.11e).
257
Fig. 10.11 3D chiral nanostructures synthesized by DNA self-assembly. a Schematics and TEM
images of a tetramer of four gold NPs assembled by double-stranded DNA. b An assemble of gold
NPs positioned by using a DNA origami bundle [59] and c its circular dichroism (top: measured,
bottom: simulated) [59]. d Four gold NPs bound in a chiral arrangement by using a DNA origami
sheet [71] and e measured circular dichroism [71]. f Twisted layer of gold nanorods stacked by using
origami sheets [65]. g Schematics of a reconfigurable 3D chiral nanostructure [72]. h Schematics
of dynamic reconfiguration. The nanorods can be switched between a tightly folded state and an
extended state, and between two folded states with opposite handedness. (a) from [67], (b) and
(c) from [59], (d) and (e) from [71], (f) from [73], (g) from [72], (h) from [74]
dressed nanospheres. 3D chiral nanostructures have been also made with a small
number of nanospheres in a tetramer arrangement [71]; to realize a chiral geometry, four binding sites were defined on a rectangular DNA origami template, i.e.,
three on the top surface and one on the bottom surface (Fig. 10.11d). The position of the binding sites on the bottom surface breaks the mirror symmetry and
determines the handedness. Four gold NPs were functionalized using complementary DNA strands and positioned, then one was positioned at each binding site by
exploiting DNA hybridization. The fabricated structure showed CD in the visible
spectrum (Fig. 10.11e).