Chiral Arrangement of Achiral Au Nanoparticles by Supramolecular Assembly of Helical Nanofiber Templates

Abstract

Chiral materials composed of organized nanoparticle superstructures have promising applications to photonics and sensing. Reliable customization of the chiroptical properties of these materials remains an important goal; hence, we report a customizable scheme making use of modular gelator components for controlling the helicity and formation of nanofibers over long length scales resulting in hydrogel templates. Controlled growth of gold nanoparticles at spatially arranged locations along the nanofiber is achieved by UV reduction of Au(I) ions on the supramolecular templates. The resulting materials were found to have significant interparticle interactions and well-defined helicity to provide high quality, chiroptically active materials. With this novel approach, the tailored assembly of nanoparticle superstructures with predictable chiroptical properties can be realized in high yield, which we expect to allow rapid advancement of chiral nanomaterials research.

Chiral plasmonics

“…Jung et al . ( 57 ) used the so-called modular gelator components, which were self-assembled into stacks and thus formed a handed hydrogel scaffold for the subsequent growth of gold nanoparticles. Because of the even smaller sizes, the chiroptical response shifted to shorter wavelengths.…”

Au Nanorod Helical Superstructures with Designed Chirality

“…A large collection of chiral plasmonic 'molecules' including gold nanoparticle (AuNP) dimers, 12,13 tetramers 14 , pyramids, 15,16 and gold nanorod (AuNR) dimers 17,18 , have been reported using DNA or protein guided self-assembly. Recently, chiral plasmonic superstructures such as AuNP helices [19][20][21][22][23] were introduced based on peptide, DNA origami or supramolecular nanofiber templates. Besides, by adsorbing AuNRs on twisted fibers or incorporating AuNRs into cellulose nanocrystal films, chiroptical activities were also found from these resulted nanocomposites.…”

Design, fabrication, and biomedical applications of bioinspired peptide–inorganic nanomaterial hybrids

“…1 In order to deeply explore the forming mechanism of NPs grown on nanofibers, Jung et al discussed the chiral helical supramolecule nanofibers with well-defined helicity for achieving the growth of organized NPs. 29 The nanofibers with different structural arrangements were identified to assembling from single to dual component mixtures. Both left-handed and right-handed helical nanofibers with anionic carboxylate groups on the surface allowed the controlled spatial arrangement of AuNPs after UV reduction.…”