Geometric Control and Optical Properties of Intrinsically Chiral Plasmonic Nanomaterials

Abstract

Intrinsically chiral plasmonic nanomaterials exhibit intriguing geometry‐dependent chiroptical properties, which is due to the combination of plasmonic features with geometric chirality. Thus, chiral plasmonic nanomaterials have become promising candidates for applications in biosensing, asymmetric catalysis, biomedicine, photonics, etc. Recent advances in geometric control and optical tuning of intrinsically chiral plasmonic nanomaterials have further opened up a unique opportunity for their widespread applications in many emerging technological areas. Here, we review the recent developments in the geometric control of chiral plasmonic nanomaterials with special attention given to the quantitative understanding of the chiroptical structure‐property relationship. We also discuss several important optical spectroscopic tools for characterizing the optical chirality of plasmonic nanomaterials at both ensemble and single‐particle levels. We further highlight three emerging applications of chiral plasmonic nanomaterials including enantioselective sensing, enantioselective catalysis, and biomedicine. We envision that these advanced studies in chiral plasmonic nanomaterials will pave the way toward the rational design of chiral nanomaterials with desired optical properties for diverse emerging technological applications.This article is protected by copyright. All rights reserved

Tuning the Geometry and Optical Chirality of Pentatwinned Au Nanoparticles with 5-Fold Rotational Symmetry

“…Subsequently, chiral pentatwinned Au NPs were synthesized in the presence of various chiral molecules, cetyltrimethyl­ammonium bromide (CTAB), ascorbic acid (AA), and Au precursors (see details in the experimental section of the Supporting Information). It has been proposed that the chiral molecules also perform as shape modifiers in addition to their role in chirality transfer, which can be attributed to their different adsorption configurations and energies with specific kink sites. , We first used CYP (cysteine–phenylalanine) and GSH (glutathione, γ-glutamic acid–cysteine–glycine) as the chiral inducers to enantioselectively interact with the Au surface and drive the formation of two distinct pentatwinned chiral structures with 5-fold rotational symmetry (Scheme B). In contrast, it is worth noting that the use of single-crystalline Au octahedral seeds for chiral growth in the presence of CYP and GSH allows for the preparation of chiral Au rhombic dodecahedrons (RDs) and chiral Au 432 helicoid III structures, , respectively (Scheme A and Figure S3).…”

“…Several strategies such as templated growth, glancing angle deposition, and chiral self-assembly have been utilized to achieve the construction of chiral plasmonic nanostructures. ,, Chiral plasmonic materials can also be artificially engineered by imparting chirality from chiral molecules into the structure of achiral crystals. ,− Recent advances in seed-mediated chiral synthesis have greatly enhanced our capabilities of fine-tuning the chiroptical properties of plasmonic NPs through deliberate control over the geometry and composition. − In particular, delicate chiral Au NPs with a symmetric point group of 432 were synthesized using peptides and amino acids as chiral inducers to encode the geometric chirality during the crystal growth processes . An alternative strategy was built on the use of chiral cosurfactants as templates for the creation of sharp chiral wrinkles on anisotropic Au nanorods (NRs) .…”

Multicomponent chiral plasmonic hybrid nanomaterials: recent advances in synthesis and applications

“…For a broader overview of the applications of plasmonic chirality, readers are encouraged to further explore excellent review articles in this field. 4,49,127,128…”

Cu2+-Dominated Chirality Transfer from Chiral Molecules to Concave Chiral Au Nanoparticles

“…Noble metal NPs exhibit remarkable geometry-dependent plasmonic chirality owing to the combination of chirality and plasmonic characteristics. − The greatly enhanced asymmetric light–matter interactions in chiral plasmonic structures have created vast opportunities for promising applications in sensing, − catalysis, , biomedicine, − and photonics. , Recent breakthroughs in seed-mediated chiral synthesis have significantly enhanced our capabilities of fine-tuning the chiroptical properties of colloidal plasmonic NPs through deliberate control over the size, shape, and composition. − By further maneuvering the seed, chiral inducers, and other key synthetic parameters in the seed-mediated chiral growth processes, chiral plasmonic NPs with distinct geometries and compositions can be generated. − While previous reports proposed that the enantioselective interaction between surfaces and chiral inducers facilitates the chirality transfer from molecules to particles during the seed-mediated chiral growth process, , how other key synthetic parameters affect the chirality transfer remains unclear. The geometric transition of the chiral NPs during seed-mediated growth is complex, entangling multiple kinetically controlled and thermodynamically driven processes that are sensitively dependent upon a variety of interplaying synthetic parameters.…”