New Optical Nano-Sensor can Precisely Measure Air Pollution

According to the World Health Organization (WHO), air pollution accounts for 550,000 premature deaths every year in Europe and seven million across the world.

However, it can be difficult to measure this claim, because the equipment is likely to be costly and bulky. But now, this may soon change as a result of a compact optical nano-sensor, devised at Chalmers. The sensor can be mounted onto a standard streetlight.

This novel technology is already being used in western Sweden, and scientists and other interested parties believe that the sensor can possibly be utilized in several broad contexts. As such, a collaboration with the University of Sheffield is also ongoing.

Air pollution is a global health problem. To be able to contribute to increased knowledge and a better environment feels great. With the help of these small, portable sensors, it can become both simpler and cheaper to measure dangerous emissions extremely accurately.

Irem Tanyeli, Researcher, Chalmers University of Technology

Tanyeli has assisted in developing the compact sensors, which are capable of determining nitrogen dioxide with excellent accuracy.

To ensure that the hi-tech sensors move from a laboratory setting to the real world, Irem Tanyeli teamed up with Insplorion—the Gothenburg-based company that was co-founded by Chalmers researcher Christoph Langhammer in the year 2010. With help from financier Mistra Innovation, Langhammer has been involved with the company’s attempts at undertaking the immense environmental challenge of accurately mapping air pollution.

This is a great example of how a university and a company can collaborate. Both parties contribute with their expertise to create a new product, contributing to a more sustainable society.

Christoph Langhammer, Professor, Department of Physics, Chalmers University of Technology

Exhaust gases from road traffic contribute to most of the nitrogen dioxide pollution present in the air. It can be detrimental to health when nitrogen dioxide—even at extremity low levels—is inhaled, and this can gas damage the respiratory systems and lead to vascular and cardiac vascular diseases.

In fact, air pollution is the single biggest environmental health risk across the world, according to the World Health Organization.

The latest optical nano-sensor is capable of detecting trace concentrations of nitrogen dioxide in a highly precise way—down to the parts-per-billion level (ppb). The measuring method is based on an optical phenomenon known as a plasmon. It emerges when light of specific wavelengths are absorbed by the illuminated metal nanoparticles. Along with his research team, Christoph Langhammer group has been working in this area for more 10 years, and now breakthroughs are beginning to see the light of day.

In the last couple of years, Irem Tanyeli has been working to improve the sensor material and was also performing tests under environmental conditions that differently simulated. At present, the new technology has been deployed to a streetlight in Gothenburg, as part of an association with lighting company Leading Light, to determine the amount of nitrogen dioxide molecules present in the urban environment.

In the future, we hope that the technology also can be integrated into other urban infrastructure, like traffic lights or speed cameras, or for measuring air quality indoors.

Irem Tanyeli, Researcher, Chalmers University of Technology

In addition, a sensor has been installed on the roof of Nordstan in Gothenburg, one of the largest shopping malls in Scandinavia, and soon more numbers of sensors will be placed along the Västlänken route, the main railway tunnel construction project, also located in Gothenburg.

The novel technology has already attracted a great deal of interest from a number of organizations that also included the Urban Flows Observatory—an air quality center at the University of Sheffield. Field testing will be carried out by them and results of the nanosensors will be compared with the data obtained from several British reference stations.

There is a lack of small functional nitrogen dioxide sensors on the market. We find this nano plasmonic solution interesting, and look forward to the test results.

Martin Mayfield, Professor, Urban Flows Observatory, University of Sheffield

Other concerned parties include Stenhøj Sverige, a company specializing in the development of smoke and gas analyzers for vehicle inspection companies and automotive repair shops, and also the Swedish Environmental Research Institute, IVL. The institute works with applied research and development in close association with industry and the public sphere to deal with environmental problems.

In addition to determining nitrogen dioxide, the latest sensor technology can also be adapted to other kinds of gases. Hence, there is great potential for more innovation.

Nitrogen dioxide is just one of the many substances which can be detected with the help of optical nanosensors. There are great opportunities for this type of technology.

Christoph Langhammer, Professor, Department of Physics, Chalmers University of Technology