Figure 1.

Structure, synthesis and properties of gold nanoclusters. A) Nanoclusters provide a link between molecular complexes and plasmonic nanoparticles. B) X-ray structure of [Au₂₅(PET)₁₈], from CSD entry JACVOB. C) Chemical structure of some of the organic thiols discussed in this review (PET: phenylethane thiol; LA: lipoic acid; GSH: glutathione; NAC: N-acetylcysteine; MTU: 5-methyl-2-thiouracil). D) Structures of biomolecular ligands (HSA: human serum albumin, PDB ID IE78; BSA: bovine serum albumin, PDB ID 3VO3, and Lys: lysozyme, PDB ID 3WUN). E) Schematic representation showing Au-BSA NC synthesis. F) Absorbance and fluorescence spectra of Au-BSA NCs. G, H) Photographs of Au-BSA NCs in solution and in the solid state under ambient light and UV light, respectively. Figure panel 1E is adapted and panel 1F is reused with permission from [63], copyright 2009 American Chemical Society. Figure panels 1G,H are adapted with permission from [64], copyright 2016 American Chemical Society.