Harnessing chirality in plasmonics: from synthesis to cutting-edge applications

Nanomaterials composed of noble metals such as gold and silver, commonly known as plasmonic materials, exhibit localized surface plasmon resonance (LSPR). LSPR significantly enhances the electric field strength, thereby influencing the optical properties, for instance in surface enhanced Raman spectroscopy (SERS). Recently, chiral nanostructures, nanostructures with broken symmetry, have demonstrated significant potential in various applications, including enantiomer detection and separation, chiral catalysis, and the development of metamaterials. Due to LSPR, these nanostructures can amplify signals such as circular dichroism (CD) and optical rotatory dispersion (ORD), making them valuable in chiroptical applications. This review provides an analysis of the synthesis, properties, and applications of chiral plasmonic nanostructures. The primary synthesis methods discussed include chemical approaches, glancing angle deposition, and focused ion beam deposition, each providing precise control over the chiral properties of the nanostructures. Furthermore, the review explores the applications of these nanostructures, particularly in the detection of biomolecules (chiral sensing), asymmetric catalysis, and the development of advanced optical devices. Lastly, the review explores future directions for the field and highlights potential areas for improvement.