Nanomaterials to help air quality measurement

Chemical sensors made from ultra-thin nanomaterials may help track air pollution better.

A team from Chalmers University of Technology in Sweden have developed a sensor that provides an “optical fingerprint” of the air.

The researchers used atomically thin transition metal dichalcogenides (TMDs) - nanomaterials that behave differently in the presence of light and gas molecules. Usually, "if you shine light on them, you don't see them," says Ermin Malic, a physicist at the university. But when gas molecules touch the surface of the sensor, the material does interact with light, producing an 'optical fingerprint', and thus detecting toxic gases in the area.

Detecting the type and amount of the gases will be important, as well as the "robustness of the nano layer," says Robert Dorey, nanomaterials expert at the University of Surrey, who was not involved in the research. "If it rubs off when touched it'll need protecting which could stop pollutants getting to it," he adds.

The researchers recently filed a patent for their technology and are now preparing to test the method in areas where air pollution is particularly bad.

Air pollution contributes to almost 40,000 deaths in the UK in a year, according to a report by the Royal College of Physicians. Money spent treating health complications caused by air pollution adds up to more than £20 billion every year, and London exceeded the annual limit of nitrogen dioxide levels five days into 2017.

The study has been published in Nature Communications.