The monitoring of trace gases at low concentration is of vital importance across a range of areas (pollutant emission measurement, process control, medical diagnostics). NOx pollution has attracted significant attention, due to the increase in diesel and nitrogen-based bio-fuels usage and the misrepresentation of pollutant levels in the automotive industry. This project will develop a highly sensitive optical sensor targeting nitric oxide (NO), which is an atmospheric pollutant and a pre-cursor to NO2, contributing to significant numbers of UK deaths per annum. Current measurement techniques cannot accurately measure NO and NO2 concentration in the atmosphere at the levels considered dangerous. As its harmful effects become increasingly apparent there is a pressing need for a step change in sensor technology, requiring two orders of magnitude improvement in sensitivity to levels lower than 500 parts per trillion (ppt) and providing improved data for analysis of pollutant species in environmental modelling.
To meet this need we will combine research from Strathclyde and Oxford University to develop a novel gas sensor, integrating the world-leading expertise from both institutions; Strathclyde- considerable expertise in cavity-based optical absorption and photoacoustic techniques for gas detection; Oxford – expertise in an advanced optical technique (optical-feedback-cavity- enhanced absorption spectroscopy - OF-CEAS). The integration of these two techniques has the potential to provide a sensitivity increase of two orders of magnitude, which translates to minimum detection sensitivities of NO and NO2 of 50ppt and 5ppt respectively, well within the range required for practical applications.