532- and 52-symmetric Au helicoids synthesized through controlled seed twinning and aspect ratio

Chiral plasmonic crystals with 5-fold symmetries were synthesized from Au icosahedra, decahedra, and pentatwinned nanorods, unraveling the effects of seed twinning and aspect ratio on chiral overgrowth directed by L-glutathione. The influence of seed size on the overgrowth from pentatwinned nanorods was also studied, giving insight into the role volumetric strain plays in chiral crystal formation. Single particle reconstructions were obtained using electron tomography, and optical simulations on the measured structures verify their optical chirality.