Design of Microfluidic Paper-Based Device for the Detection of Nitrogen Dioxide in Atmosphere

Pollutant gases from industries and certain processes like welding, exhaust of internal combustion engines, use of explosives, use of nitric acid, etc., are the sources of sulfur dioxide (SO2) and nitrogen oxides (NO2 and N2O5) which become the part of atmosphere. The heterogeneous reactions of atmospheric aerosol convert these gases to sulphuric, nitrous, and nitric acids which precipitate as acid rain and thus severely affect human health. In this paper, the design of colorimetric paper-based microfluidic device is presented to detect and quantify nitrogen dioxide (NO2). In order to reduce the cost of device and ease of fabrication, wax printing for fabricating paper-based analytical device (µPAD) is proposed.