Plasmonic circular dichroism using Au fine particles and riboflavin

We report circular dichroism (CD) induced in the visible region using a composite film containing Au fine parti-cles and riboflavin. It is revealed that binding of chiral molecules to the surface of Au fine particles is not necessary for the plasmon-induced CD. Moreover, we find that composite films containing dye and glucose instead of Au fine particles and riboflavin induces a CD signal at the wavelength, where the dye shows an absorption peak. The polarity of the CD signal is reversed by using the enantiomer of glucose. Mechanism of the absorption-induced CD in the visible region is discussed.