Measuring mercury with a Midas touch

Nano-gold spikes magnified 200,000 times. Credit: RMIT
Nano-gold spikes magnified 200,000 times. Credit: RMIT

RMIT University researchers have used nanotechnology to create a pioneering sensor that can precisely measure one of the world’s most poisonous substances—mercury.

The mercury sensor developed by RMIT’s Industrial Chemistry Group uses tiny flecks of gold that are nano-engineered to make them irresistible to mercury molecules.

Efforts to reduce mercury contamination in the environment and associated health risks rely on being able to accurately measuring the toxin, a priority for mercury-emitting industries like coal-burning power generators and alumina refineries.

Prof. Suresh Bhargava, Dean of the School of Applied Sciences, says traditional mercury sensors could be unreliable.

“Industrial chimneys release a complex concoction of volatile organic compounds, ammonia and water vapour that can interfere with the monitoring systems of mercury sensors,” Suresh says.

“We wanted a sensor that would be robust enough to cope with that kind of industrial environment but also sensitive enough to give precise readings of the amount of mercury vapour in these emissions.”

The RMIT researchers used patented electrochemical processes to alter the surface of the gold, forming hundreds of tiny nano-spikes, each one about 1,000 times smaller than the width of a human hair.

The nano-engineered surfaces are then used with existing measuring technologies to determine the levels of mercury in the atmosphere.

For more information: RMIT University, Gosia Kaszubska, Tel: +61 (3) 9925 3176, +61 417 510 735,