Recently, Prof. Gao Xiaoming's group from the Anhui Institute of Optics and Fine Mechanics (AIOFM) of the Hefei Institutes of Physical Science (HFIPS) designed and manufactured a photoacoustic spectroscopy-based sensor to measure aerosols and nitrogen dioxide (NO2) simultaneously.
source https://phys.org/news/2021-01-sensor-atmospheric-aerosols-nitrogen-dioxide.html
