Chiral Plasmonic Nanoparticles From An Achiral Template

Chiral plasmonic nanoparticles have been predicted to exhibit both strong circular dichroism in the visible spectral range and non-linear optical effects. These properties open up applications for chiral nanoparticles in sensing, enantiomer separations, and non-linear optics. Unfortunately, to date the fabrication of colloidal nanoparticles with chiral shape has posed a significant challenge due to a very limited ability to transfer chirality from chiral template molecules to nanoparticles.  Here we report a novel route to enantiopure chiral gold nanoparticles.  Importantly, we do not use in principle any chiral molecules or biomolecules and therefore create chiral shapes artificially.  Template stripping is applied to achiral silicon wafers to prepare nanoparticles with chiral shape of only one handedness and with sizes between 100 nm and 1 micron. Both experimental and simulated circular dichroism spectra from suspensions of the template-stripped chiral nanoparticles will be discussed.