Australian researchers are working on a portable, highly sensitive method for gold detection, which could allow mineral exploration companies to test for gold on-site.

Using light in two different processes (fluorescence and absorption), the researchers from the University of Adelaide have been able to detect gold nanoparticles at detection limits 100 times lower than achievable under current methods.

It could improve Australia’s position as one of the world’s largest gold producers, with the local industry currently worth $13 billion in export earnings.

“Exploration for gold is extremely challenging with a desire to detect very low concentrations of gold in host rocks," says postdoctoral researcher Dr Agnieszka Zuber.

"The presence of gold deep underground is estimated by analysis of rock particles coming out of the drilling holes. But current portable methods for detection are not sensitive enough, and the more sensitive methods require some weeks before results are available.

"This easy-to-use sensor will allow fast detection right at the drill rig with the amount of gold determined within an hour, at much lower cost."

In tests so far, researchers have been able to detect less than 100 parts per billion of gold in water.

The results from the latest research will be presented at the IPAS Minerals and Energy Sector Workshop this week.

The ongoing gold detection work is funded by the Deep Exploration Technologies Cooperative Research Centre.