Researchers at the University of Adelaide in South Australia have created a laser that can “smell” different gases within a sample.
The researchers liken the ability of the laser to differentiate between different gas compounds in a sample to the sensitive nose of a bloodhound. But rather than smell, the device uses patterns of light absorption to measure the composition of the sample.
From the University’s Institute for Photonics and Advanced Sensing (IPAS), the researchers report in the journal Physical Review Applied that the laser can measure the amount of carbon dioxide in a gas sample in less than a second, with high accuracy and precision.
The potential for this instrument lies in pairing it with cutting edge medical research on ‘breath analysis’; detecting molecules that are by-products of metabolic processes in the body when things go wrong.
Lead author and PhD candidate in the University of Adelaide’s School of Physical Sciences Sarah Scholten said the laser’s ability to rapidly measure gas composition with such high accuracy was “cutting edge”.
“With further development, it opens the way for real-time and inexpensive monitoring and analysis that can be carried out in the field, or in the doctor’s surgery, by non-specialist operators,” she said.
The device exploits a Nobel-prize winning technology, developed by US and German scientists, called an optical frequency comb.
The comb is essentially a broadband light source made up of millions of distinct, equally spaced laser sources. This appears as a rainbow of light to the naked eye, but the discrete laser sources can be made out under magnification.
The researchers pass this special light through a sample of gas where each gas molecule absorbs a distinctive set of colours. The pattern of light absorption is a unique fingerprint of the gas composition of the sample.
The device also has potential applications in environmental monitoring and detecting industrial contamination.
“This first work aims at atmospheric monitoring, however, the technique is broadly applicable and offers an avenue for near-universal concentration measurements,” Postdoctoral Fellow Dr Chris Perrella said.
The group now aims to use the laser comb to unravel the chemical composition of exhaled breath. In this much more complex situation they hope to find telltale chemical signs that point to underlying disease. The ultimate goal is to use the laser as a screening tool to “smell the breath” to discover a serious illness even before the patient is aware of the condition.
The research was led by IPAS Director Professor Andre Luiten and was funded by the Australian Research Council, Medical and Scientific Services Pty Ltd, the South Australian Premier’s Research and Industry Fund and a South Australian Government Catalyst Research Grant.Jump to next article