Enhanced optical asymmetry in supramolecular chiroplasmonic assemblies with long-range order

Nanorod alignment for optical asymmetry The high polarizability of chiral nanoassemblies of plasmonic nanoparticles can lead to strong chiral dichroism, but strong light scattering causes the fraction of polarized photons generated, as measured by g-factors, to be much lower than that for chiral liquid crystals. Lu et al. used supramolecular interactions of gold nanorods with human islet amyloid peptides to assemble metallic superstructures with unusually high cholesteric order (see the Perspective by Nam and Kim). The long, straight helices increased the g-factor by 4600-fold, and this effect was used to screen small-molecule binding to amyloids. Science , this issue p. 1368 ; see also p. 1311