Patternable chiral Au nanocrystal-doped composite films for information encryption: the role of optical rotation.

Optical information encryption technology has garnered significant attention in currency security, information protection, and personal identification. While optical metasurfaces are considered ideal platforms for information encryption, their high cost and time-intensive fabrication processes have limited their widespread applications. To address this, emergent chiroptical nanomaterials offer new opportunities for information encryption through their polarization capabilities.

Chiral plasmonic-dielectric coupling enables strong near-infrared chiroptical responses from helicoidal core-shell nanoparticles.

Helicoid plasmonic nanoparticles with intrinsic chirality are an emerging class of artificial chiral materials with tailorable properties. The ability to extend their chiroplasmonic responses to the near-infrared (NIR) range is critically important for biomedical and nanophotonic applications, yet the rational design of such materials remains challenging. Herein, a strategy employing chiral plasmon-dielectric coupling is proposed to manipulate the chiroptical responses into the NIR region with high optical anisotropy.

Enantioselective Surface-Enhanced Raman Scattering by Chiral Au Nanocrystals with Finely Modulated Chiral Fields and Internal Standards.

The chiral discrimination of enantiomers is crucial for drug screening and agricultural production. Surface-enhanced Raman scattering (SERS) is proposed for discriminating enantiomers benefiting from chiral plasmonic materials. However, the mechanism of enantioselective SERS is unclear, and fluctuating SERS intensities may result in errors.

Surface Topographical Engineering of Chiral Au Nanocrystals with Chiral Hot Spots for Plasmon-Enhanced Chiral Discrimination.

Surface roughness in chiral plasmonic nanostructures generates asymmetrical localized electromagnetic fields, which hold great promise for applications in chiral recognition, chiroptical spectroscopic sensing, and enantioselective photocatalysis. In this study, we develop a surface topographical engineering approach to precisely manipulate the surface structures of chiral Au nanocrystals. Through carefully controlling the amounts of l- or d-cystine (Cys) and the seed solution in the growth process, we successfully synthesize chiral Au nanocrystals with highly disordered, ordered, and less ordered wrinkled surfaces.

Synthesis of Chiral Au Nanocrystals with Precise Homochiral Facets for Enantioselective Surface Chemistry.

Metal surfaces with intrinsic chirality play an irreplaceable role in many significant enantioselective chemical processes such as enantioselective catalysis, sensing, and separation. Nonetheless, current methods for the precise preparation of such chiral surfaces suffer with issues of unscalable production and low surface areas. Herein, we report the synthesis of chiral Au nanoparticles with precisely determined homochiral facets.