Particle reflection

Advances in nanofabrication have enabled studies of chirality to extend from conventional ‘mirror image’ molecules seen in organic chemistry to three-dimensional metallic nanostructures. Similar to their organic counterparts these metallic structures display optical activity with each mirror-image form interacting differently with circularly polarized visible light. This optical activity is rooted in plasmonic effects which derive from the way the structures’ morphology affects oscillations of electrons in the material. In this issue Ki Tae Nam and his colleagues demonstrate a solution-based method for synthesizing homogenous highly chiral gold nanoparticles and controlling their respective chiral properties. The researchers induce chirality by growing the gold in the presence of cysteine or cysteine-based peptides which enantioselectively bind to high-index crystallographic planes of the gold seeds. The process could lead to new opportunities in chiral sensing and active colour displays