©  Copyright 2013 Nanotechnology researchers are looking into possibilities of  using gold at the nanoscale to target drug deliveries, clean up  the environment, and even treat persons suffering from  hyperthermia. Gold is an element used in jewelry, coins,  dentistry, and electronic devices. Gold is even used in some  medicines. Bulk gold is considered an inert material in that it  doesn’t corrode or tarnish. As with all metals, gold has good  electrical and thermal conductivity. Gold’s capability to resist  corrosion as well as its high electrical conductivity make it  useful for forming contacts in electronic devices.  Gold has been used in various medical treatments over the centuries without harmful effects. It was  therefore natural for researchers to look to gold nanoparticles for medical applications rather than using  elements such as platinum, which can be toxic in certain circumstances. Forming gold into nanoparticles  allows researchers to use gold in areas that are too small for bulk gold to reach and brings with it new  capabilities.  For targeted drug delivery uses, it will be interesting to see whether gold nanoparticles show any  benefit versus cheaper types of nanoparticles, such as iron nanoparticles. For other uses, gold  nanoparticles have some clear advantages.  When gold nanoparticles get really small, with a diameter of 5 nm or less, they can be used as a  catalyst to help reactions that, for example, transform air pollutants into harmless molecules.  Using gold to clean up the air is somewhat surprising given that bulk gold is considered to be an inert  material. Normally, gold would be a silly material to use as a catalyst for chemical reactions because it  doesn’t do much. However, if you break down gold to nanosize (approximately 5 nanometers), it can act  as a catalyst that can do things such as oxidizing carbon monoxide.  Researchers attach molecules to gold nanoparticles that are attracted to diseased regions of the body,  such as cancer tumors, and other molecules such as therapeutic drug molecules. This enables the  functionalized gold nanoparticles to be used in targeted drug delivery.  Chemical Engineering & Gas Processing