Researchers from the Tyndall National Institute based at the University College Cork, Ireland, are developing a method for detecting mercury using gold.
The researchers found that individual gold nanorods could be used to make smaller, portable mercury sensors that could test for the metal in soil, water and air.
An individual gold nanorod was attached to a glass slide and placed under an electron microscope.
Using an imaging method called dark field microscopy, the team studied the composition of the sample by measuring how light scatters off the rod’s surface.
A gold nanorod produced a red wavelength pattern but when dipped in a solution containing traces of mercury, the rod’s shape and composition changed, producing an orange wavelength pattern.
The greater the amount of mercury in the solution, the more the wavelength changed.
The nanorods were also found to have a higher sensitivity to mercury compared to other metals including nickel, lead, magnesium and copper.
“The reported linear correlation and high selectivity make this approach potentially suitable for on-site analysis using a miniaturised portable spectrometer,” the study indicated.
However, some obstacles remained, such as the need to produce consistently shaped gold nanorods for more accurate measurements. There is also the need for pre-purification protocols of the rods before real world analysis can be conducted.
The research findings were published in the Science and Technology of Advanced Materials journal.