STEM Tomography of Au Helical Assemblies

Abstract

Abstract

Quantification of the Helical Morphology of Chiral Gold Nanorods

“…Chiral features in metal nanoparticles (NP) result in chiroptical properties, of interest to many applications, such as enantioselective catalysis or separation, chiral sensing, drug delivery, and the generation of circularly polarized light (CPL). − These applications arise from the different interactions of chiral plasmonic NPs with left- and right-handed CPL. Therefore, much effort has been put into the development of NPs with complex structures and morphologies. − The properties of such nanomaterials are usually characterized by measuring their circular dichroism (CD), which quantifies the interaction of an ensemble of particles with CPL . Under certain conditions, such measurements can also be performed for single nanoparticles, which may help account for heterogeneity in morphology and optical response. − Multiple factors can be at the origin of the recorded CD signal, such as a chiral morphology, chiral features in the crystalline structure, or the presence of chiral molecules at or near the surface of the chiral NPs. ,,− To obtain NPs with tailored chiroptical properties, it is thus important to understand the connection between the CD signal and the NP morphology.…”