Gold has long been known to have size-dependent catalytic activity. The metal is inert in bulk, whereas gold nanoparticles 3 to 5 nm in diameter can catalyze a variety of reactions. But those larger nanoparticles require the addition of H2 or peroxide species to drive the reaction, or an electronic interaction with a support material such as titanium dioxide.

Nanometre-scale gold particles are currently intensively investigated for possible applications in catalysis, sensing, photonics, biolabelling, drug carriers and molecular electronics. Supported nanosized gold particles have shown remarkable catalytic properties even for the oxidation of CO. There are potentials for exploitation of gold nano particles for a variety of applications including environmental pollution abatement, sensors and various other chemical and biochemical applications.

The chemical process of preparing such particles is well known and many different stable sizes and compositions are also known. But the definite information of their atomic structure is not well known but for the work at Stanford University and University of Jyväskylä in Finland.
Researchers in the Department of Chemistry and the Nanoscience Center (NSC) at the University of Jyväskylä, in collaboration with the Kornberg group, report the first full spectroscopic characterisation of the absorption of electromagnetic radiation by the Au102(p-MBA)44 particle in solution and solid phases. The work also establishes the molecular nature of the clusters.