Biomedical Engineering Reference
In-Depth Information
that this CD induction was governed by a long-range Coulomb and
electromagnetic interaction, which could be modeled as a dipolar
coupling (see Fig. 1.21a). In the case of the monolayer-coated silver
particles, the observed significantly induced plasmonic CD (Fig.
1.21d) could only be interpreted and modeled by the formation of
MNPs with a slight chiral shape distortion (Fig. 1.21c).
NCs with chiral shapes, both plasmonic and semiconductor,
represent currently an active field of technology and research [9,
46, 56, 76]. Chemical synthesis of such NCs often involves chiral
molecules that participate in some way in growth of NCs. Detailed
mechanisms of the chiral growth are needed to be investigated and
developed further.
To finalize this section, we should mention the recent work
on lithographically made plasmonic metamaterial structures with
chirality. 3D chiral nanostructure can be fabricated using a non-
chiral quasi-2D metamaterials (plasmonic crosses) and a layer
of chiral molecules (Fig. 1.22a). The resulting CD spectrum
Figure 1.22
(a) Plasmonic Au crosses covered with a layer of chiral mole-
cules exhibit a plasmon peak in the CD spectrum. Adapted with permission
fromRef.[1].Copyright2012,AmericanChemicalSociety.(b)Lithographical
plasmonic oligomer structures exhibiting strong directional CD. Adapted
withpermissionfromRef.[38].Copyright2012,AmericanChemicalSociety.
