Deliberate Introduction of Particle Anisotropy in Helical Gold Nanoparticle Superstructures

Helical nanoparticle (NP) superstructures are an important class of chiral NP assemblies. The nature of the constituent NPs (size and shape) within these assemblies dictates their optical properties. However, the construction of helical NP superstructures consisting of various anisotropic NPs remains challenging. Here, a set of cetyltrimethylammonium bromide derivatives is employed to transform constituent spherical gold NPs (approximate to 3 nm) within a chiral single-helical assembly into gold nanoprisms (edge length approximately equal to 10 nm). Careful optimization of this strategy may lead to designed chiral NP architectures with tunable optical properties.