Chiral plasmonic nanostructures have opened up unprecedented opportunities in optical applications. We present chirality evolution in nanoparticles focusing on the crystallographic aspects and elucidate key parameters for chiral structure formation. From a detailed understanding of chirality formation, we achieved a morphology (432 Helicoid IV) of threedimensionally controlled chiral plasmonic nanoparticles based on the rhombic dodecahedral shape. The role of the synthesis parameters, seed, cysteine, cetyltrimethylammonium bromide and ascorbic acid on chiral formation are studied, and based on this understanding, the systematic control of the chiral structure is presented. The relation between the modulated chiral structure factors and optical response is further elucidated by electromagnetic simulation. Importantly, a new optical response is achieved by assembling chiral nanoparticles into a film. This comprehensive study of chiral nanoparticles will provide valuable insight for the further development of diverse chiral plasmonic nanostructures with fascinating properties.

Here, we will discuss the principles of recent issues in chiral sensing of plasmonic metamaterials, including suggested formulas for signal enhancement of chiral plasmonic sensors, and studies on platforms that employ different sensing mechanisms.

and their microscopic assembling and folding gradually give rise to chirality and left-right asymmetry from supramolecules to organelles, cells, and macroscopic organisms. Although the origin of homochirality is still unexplained and opens to arguments, investigating the chirality of matter and its origination is a central part of understanding asymmetric physical and chemical phenomena. The importance of chirality in chemistry lies in the asymmetric biochemical reactions with different physiological effect, which has paramount importance in biochemistry and pharmaceutical industry. [3,14,15] A mirror image of chiral objects can be determined into one of the left-handed or right-handed forms of geometry, called enantiomer or enantiomorph. Both enantiomers of a chiral object consist of identical chemical compositions but indeed are significantly different in their light-matter interaction, catalysis, and biological functions. The enantioselective signaling and enzymatic reaction are attributed to the homochirality of the living organism and its biological receptors, which are only composed of l-form amino acids and d-form sugars in nature. [7,14,15] Thalidomide is often referred to as a representative but also the most tragic example. The R-form of this drug is harmless to the body and was released as a painkiller for pregnant women, but its enantiomer causes severe malformation in the limbs of infants. [15,16] Since then, it has been a requirement for drugs to be characterized as a single enantiomer to be approved. 3D chirality is a unique characteristic of life, and the stereochemical aspect of molecular materials has come to fore of modern chemistry and biology. The optical property of chiral compounds, the so-called chiroptical effect, is highly effective for observing chirality in a nondestructive manner. [17] Chiroptical effects can be used for determination of the absolute configuration and enantiomeric excess of chiral molecules and as an optical probe for estimating the 3D structure of biomacromolecules such as proteins and DNA. [18] However, in most chiral organic molecules and biomolecules, chiroptical effects are typically very weak due to the much smaller size of molecules than the wavelength of exciting light. Integration of inorganic nanomaterials is one promising method for increasing the chiroptical signal of molecules; it focuses the light into nanoscale area to maximize the lightmatter interaction. [19-22] For example, a complex spatial profile Chirality is a basic property of nature and has great importance in photonics, biochemistry, medicine, and catalysis. This importance has led to the emergence of the chiral inorganic nanostructure field in the last two decades, providing opportunities to control the chirality of light and biochemical reactions. While the facile production of 3D nanostructures has remained a major challenge, recent advances in nanocrystal synthesis have provided a new pathway for efficient control of chirality at the nanoscale by transferring molecular chirality to the geo...