According to the World Health Organization, air pollution is one of the greatest environmental health risks globally, with approximately 7 million deaths on Earth attributed to air pollution. Vehicle emissions are a major source of nitrogen dioxide pollution. Inhalation of nitrogen dioxide is harmful even at very low levels, potentially damaging the respiratory system and causing cardiovascular diseases. Therefore, monitoring nitrogen dioxide in the air is critical.

Although there are multiple methods for monitoring nitrogen dioxide in air, including ground-based sensors and orbital satellites, air quality monitoring devices are often large and expensive. Researchers at Chalmers University of Technology in Sweden have developed a new type of optical nano sensor that can be installed on ordinary street lamps. This technology is already in use in western Sweden, and researchers hope it can be deployed widely, attracting interest and testing from various organizations.

Optical nano sensors in ordinary street lamps application

These small, portable sensors can measure hazardous emissions very accurately and are simple and inexpensive. This new optical nano sensor can detect very low concentrations of nitrogen dioxide. This measurement technology is based on an optical phenomenon called plasmonics, which occurs when metal nanoparticles are illuminated and absorb certain wavelengths of light.

Optical nano sensors measure wavelength changes when metal nanoparticles are illuminated, allowing detection of nitrogen dioxide and other gases. "Nitrogen dioxide is just one of many substances detectable by optical nano sensors," developers state. There is a lack of compact functional nitrogen dioxide sensors on the market. They find this nano-plasmonic solution interesting and look forward to testing results.

Currently, air quality sensors for detecting air pollution and purifying air include PM2.5 sensors, dust sensors, infrared sensors, and laser dust sensors from Lefmai.