Hydrophobic Gold Nanoparticles with Intrinsic Chirality for the Efficient Fabrication of Chiral Plasmonic Nanocomposites

Abstract

The development of plasmonic nanomaterials with chiral geometry has drawn extensive attention owing to their practical implications in chiral catalysis, chiral metamaterials, or enantioselective biosensing and medicine. However, due to the lack of effective synthesis methods of hydrophobic nanoparticles (NPs) showing intrinsic, plasmonic chirality, their applications are currently limited to aqueous systems. In this work, we resolve the problem of achieving hydrophobic Au NPs with intrinsic chirality by efficient phase transfer of water-soluble NPs using low molecular weight, liquid crystal-like ligands. We confirmed that, after the phase transfer, Au NPs preserve strong, far-field circular dichroism (CD) signals, attesting their chiral geometry. The universality of the method is exemplified by using different types of NPs and ligands. We further highlight the potential of the proposed approach to realize chiral plasmonic, inorganic/organic nanocomposites with block copolymers, liquid crystals, and compounds forming physical gels. All soft matter composites sustain plasmonic CD signals with electron microscopies confirming well-dispersed nanoinclusions. The developed methodology allows us to expand the portfolio of plasmonic NPs with intrinsic structural chirality, thereby broadening the scope of their applications toward softmatter based systems.

Biomimetic Chiral Nanomaterials with Selective Catalysis Activity

“…The existence of chiral ligands caused the synthesis of twisted chiral geometry in the synthesis process of chiral metal NPs, which further endowed chiral metal NPs with remarkable CD signals. [3,62,63] The configuration of introduced chiral ligands determined the handedness of chiral geometry. In particular, Cys enantiomers induced the formation of cube-like Au NPs with side sizes of 150 nm and the appearance of split edges.…”

A cooperation tale of biomolecules and nanomaterials in nanoscale chiral sensing and separation

“…The design of chiral plasmonic NMs has received considerable interest owing to their potential applications in various domains such as material science, medicine, and nanotechnology. [49][50][51] DNA nanotechnology provided efficient approaches for designing chiral templates of different geometries. To fabricate desirable chiral plasmonic systems, nanostructures synthesized by the self-assembly of DNA have been efficiently employed as templates.…”

Engineering copper plasmonic chirality via ligand-induced dissolution for enantioselective recognition of amino acids

“…[22][23][24] The generation of chirality and its intriguing applications are well explored in plasmonic nanomaterials, such as gold and silver. [25][26][27] However, the fundamental understanding and applicability of chiral copper nanoparticles (CuNPs) is an area that remains underdeveloped. Owing to their excellent electrical and thermal properties, comprehended by their unique optical response in the visible and near-infrared regions, copper nanomaterials that are relatively inexpensive are emerging as viable alternatives to precious metals like gold and silver in various plasmonic applications.…”