Uniform Chiral Gap Synthesis for High Dissymmetry Factor in Single Plasmonic Gold Nanoparticle.

: Synthesis of chiral plasmonic material has been highlighted for the last decades with its unique optical properties and versatile potential applications. Recently reported aqueous based amino- acid-and peptide-directed synthesis of chiral plasmonic gold nanoparticles with unique 432 point-group symmetry shows exceptionally high chiroptic response within 100 nm scales. Despite its already excellent chiroptic response, single nanoparticle dark field scattering study revealed that full chiroptic potential of chiral gold nanoparticle is limited with its overall synthetic uniformity. Based on this knowledge, we present a multi-chirality-evolution step synthesis method for the enhancement of chiroptic response through increase in particle uniformity. Detailed time variant study and interrelationship study of reaction parameters allowed the systematic construction of design principles for chiral nanoparticle with exceptional chiroptic response. With the application of precisely controlled growth kinetic to two distinct growth regimes, modified chiral gold nanoparticle showed significantly improved uniformity, achieving improved dis-symmetry factor of g = 0.31. We expect that our strategy will aid in precise morphology and property control for chiral nanomaterials which to be used in various plasmonic metamaterial applications.