Edge-directed rapid chiral assembly of gold nanorods by 2D hexagonal nanosheets of helical poly(phenylacetylene)s and the synergistic communication of circularly polarized luminescence

Abstract

Two-dimensional (2D) materials with a unique planar geometry have garnered significant attention. The high-energy edges of 2D materials, distinct in structure and properties from large surfaces, enable post-modification for novel hybrid materials but remain rarely explored. Here, this work proposes a co-assembly strategy to fabricate chiral hybrid materials by templating gold nanorods (GNRs) along the edge of 2D poly(phenylacetylene) (PPA) nanosheets, enabling their arrangement into chiral assemblies. This approach achieves rapid chiral packing of GNRs, yielding strong plasmonic circular dichroism (PCD) signals with the maximum dissymmetric factor g_abs ∼ ±0.05 within one minute. Unlike large surfaces, the edges of nanosheets induce GNRs to align at specific tilted angles by the helicity of PPA side chains, as confirmed by simulated circular dichroism (CD) and extinction spectra of the chiral GNR assemblies. Furthermore, the resulting chiral hybrid nanostructures significantly enhance the circularly polarized luminescence (CPL) of PPA nanosheets, establishing their potential as chirality filters. The strong coupling between the GNRs and PPA side groups is attributed to multiple non-covalent interactions, as demonstrated by Raman, electronic circular dichroism (ECD), and vibrational circular dichroism (VCD) spectroscopies. This study underscores the synergistic communication between polymeric 2D assemblies and inorganic nanoparticles in the development of advanced chiral materials.