(70a) Functional Chiral Nanostructures

The early observation of strong circular dichroism for individual nanoparticles (NPs) and their assemblies have developed into a rapidly expanding field of chiral inorganic nanostructures. They encompass a large family of mirror-asymmetric constructs from metals, semiconductors, ceramics, and nanocarbons with multiple chiral geometries with characteristic scales from Ångströms to microns (Figure 1). Versatility in dimensions and polarizability of the inorganic materials enables their multiscale engineering to attain a broad range of optical and chemical properties. These capabilities as chiral materials enabled their fast technological translation for biosensing and optoelectronics, which, in turn, opened new venues for scientific inquiry into the unifying role chirality at the interface of materials science, biology, chemistry, and physics.

This talk will address (1) the origin of the uniquely high values of optical anisotropy; (2) mechanisms of chirality transfer in inorganic materials; and (3) differences/similarities with chiral supramolecular, liquid crystal, and biological assemblies. Emerging venues for practical realizations of chiral inorganic nanoassemblies related to circular polarization spectroscopy in terahertz spectral window will be discussed.

References :

Kotov, N.A. Inorganic Nanoparticles as Protein Mimics Science, 2010, 330, 188.

Chen, W. et al. Nanoparticle Superstructures Made by PCR: Collective Interactions of Nanoparticles and a New Principle for Chiral Materials. Nano Lett. 2009, 9(5), 2153.

Srivastava, S.; et al Light-Controlled Self-Assembly of Semiconductor Nanoparticles into Twisted Ribbons. Science, 2010, 327, 1355–1359.

J.Yeom, et al Chiral Templating of Self-Assembling Nanostructures by Circularly Polarized Light, Nature Mater. 2015, 14, 66.

Jiang, et al. Chiral Ceramic Nanoparticles of Tungsten Oxide and Peptide Catalysis, JACS, 2017, 139, 13701.

Yeom et al, Chiromagnetic Nanoparticles and Gels, Science. 2018, 359 (6372), 309-314.

Choi et al, Kirigami Modulators for Terahertz Chiroptical Spectroscopy, Nature Materials, 2019, 18, 820–826.

W.Jiang, et al Emergence of Complexity in Hierarchically Organized Chiral Particles, Science, 2020, 368, 6491, 642-648.