Gold is one of the first metals to have been discovered; the history of its study and application spans at least several thousand years. Despite the long relationship between humans and this precious metal, new properties continue to be discovered. The latest developments are at the nanoscale. A recent study has found that gold atoms — which are not quite enough in number to form metal — can store power from light.
The research came about after scientists discovered that chemical changes in the electronic properties of nanometer-sized chunks of gold occur when a beam is shone into the molecular structure.
The gold nanoparticles were created by collecting a small quantity of gold — just 102 atoms — and stabilising the molecules using a ligand layer. It takes 144 gold atoms to form a material that be classed as a “metal.” At the nanoscale molecular level, molecules behave very differently to an actual metal.
By shining light on the stabilized particles, the researchers noted that the gold can capture and store energy at the nanoscale level. This showed that gold atoms have photophysical properties.
At present, most of the studies have been carried out using computer models. The next trick will be harnessing the energy in ways that are practical and useful.
The implications of the research are that tiny quantities of gold nanoclusters can be used for the short-term storage of energy. This could be used in medical research for bio-imaging. A similar alternative would be with storing an electric charge for use with molecular electronics.
The study was carried out at the Nanoscience Center of the University of Jyväskylä, Finland.
The findings have been published in the journal ACS Nano. The paper is titled “Molecule-Like Photodynamics of Au102(pMBA)44 Nanocluster.”
In related news, gold nanoparticles are emerging as promising agents for cancer therapy and are being investigated as drug carriers, photothermal agents, contrast agents and radiosensitisers.