The shape anisotropy of nanoparticle building blocks is of critical importance in determining their packing symmetry and assembly directionality. While there has been extensive research on the effect of their overall geometric shapes, the importance of nanometer morphology details is not well-recognized or understood. Here we draw on shape-anisotropic gold triangular nanoprism building blocks with either morphology details on their tips or their side facets as examples of demonstration. By fine-tuning the balance among internanoparticle interactions, we observed a series of unexpected polymorphic assemblies with unique plasmonic coupling properties. [1,2] Our study can guide future work in both nanoparticle synthesis and self-assembly; nanoscale geometrical features in anisotropic nanoparticles can be used as an important handle to control directional interactions for nonconventional ordered assemblies and to enrich diversity in self-assembly structure and function.
Ref (1): Nano Letters 17 (5), pp 3270–3275 (2017).
Ref (2): Nature Communications, 8, 761 (2017)