Why is gold such a perfect material for a wide range of applications? Which characteristics make it so ideal? One of the most important characteristics of gold is its nobility and the resistance it has to surface oxidation. Unlike other metals where surface oxidation might cause problems with the operation of nanoscale technologies based upon them. Another great characteristic of gold are its optical properties at the nano-scale. The color of gold nanoparticles varies from red to purple, depending on the size of the particle. For a wide range of applications this property can be exploited successfully.

In addition, these days it is known that nanoparticles of gold can act as a catalyst for a wide range of important commercial reactions. Furthermore, these  gold particles are very suited to attach with sulphur-containing molecules (like thiols), due to their special surface chemistry, and this allows ‘bottom-up’ assembly of very useful and interesting structures.

As a result of these unique characteristics of gold, a lot of new and exciting nanotechnologies using gold have been developed. Some examples are:

• Fuel cell electrocatalysts based on carbon supported nanoparticulate gold

• Nanoparticulate gold catalysts for pollution control and chemical synthesis

• Gold nanoparticle containing paints and textiles exhibiting novel aesthetic effects

• Improved decorative coatings using thiol stabilised gold nanoparticles

• Gold nanoparticles used for targeted delivery of anticancer drugs and destruction of cancer cells

• Nanoparticulate gold colloid for rapid tests and biomedical assays

• Gold nanowires for interconnections in future electronic devices

• Low resistance printable gold nanoparticulate inks for flexible electronics