CHIRAL FLUORESCENT GOLD NANOCLUSTERS

Chiral fluorescent metal nanoclusters are worthy of attention owing to their potential applications in chemistry and biology. Here, fluorescent gold nanoclusters (Au NCs) reduced by L-histidine (L-his) and D-histidine (D-his) respectively were synthesized and observed to be optically active. Circular dichroism (CD) spectra revealed a distinct mirror image relationship between the L-his-Au NCs and the D-his-Au NCs. And the CD signals of both Au NCs in the range of 260 nm to 360 nm differed from those of the free L-his and D-his. While the Au NCs reduced by DL-histidine (DL-his) showed no CD activity. L-his-Au NCs and D-his-Au NCs as well as the DL-his-Au NCs exhibited the same fluorescence emission spectra when excited at 386 nm. The origin of the circular dichroism of the Au NCs is discussed preliminarily.