Intense Plasmon-induced Cotton Effects in Colloidal Silver Triangular Nanoplates Synthesized by a Ligand-exchange Process

Chiroptically active Ag triangular nanoplates were synthesized by the ligand-exchange reaction of achiral Ag nanoplates with chiral D- or L-penicillamine molecules. Analysis of the chiroptical properties of the synthesized nanoplates by circular dichroism spectroscopy revealed intense Cotton effects, with wavelengths that corresponded to those of the surface plasmon resonances for the nanoplates. Enantiomeric excess and pH dependence of these effects were also measured to explore the origin of the chiroptical activity of the nanoplates.