Extended Data Fig. 2: Chiral morphology development of 432 helicoids I and II.
From: Amino-acid- and peptide-directed synthesis of chiral plasmonic gold nanoparticles
a, Schematic illustration of stellated octahedron with differentiated {321} facets ({321} nanoparticle). Each triangular facet of a stellated octahedron is divided into two convex {321} facets with R and S surface conformation. b, SEM images showing the detailed geometry of a {321} nanoparticle. c, Bright-field TEM image along the [110] direction showing angles (α, β, γ) between the eight outermost edges. d, Calculated angles between the outermost edges of an {hkl}-enclosed nanoparticle. The exposed facets of the nanoparticle in c were indexed as {321}. e, Schematic illustration of the time-dependent evolution of 432 helicoids I and II. All models are viewed along the [110] direction. Starting from a {321}-indexed nanoparticle with an equal ratio of R and S regions, different R–S boundaries are split, thickened and distorted. f, SEM images of 432 helicoids I and II at different growth times. The chiral components that developed in 432 helicoids I and II are highlighted in red and blue, respectively.
