Nitrous oxide sensing
Nitrous oxide is implicated in fossil fuel combustion, is extensively used in aerosols, medicine (anaesthetic/analgesic), and reported to be the second most widely used recreational drug in the UK. It is also the product of heating/detonation of ammonium nitrate fertiliser, and is known to be a greenhouse gas three hundred times more potent than CO2. Numerous health problems including sensory neuropathy, asphyxiation, anaemia and reproductive problems have been linked to nitrous oxide exposure. 8-hour occupational exposure limits, in the NHS, are set at 50 ppm.
Few technologies are able to selectively identify nitrous oxide, and colorimetric detection by a single component system is unknown. Reversible binding of nitrous oxide needed for a ‘real time’ sensor is unprecedented. Oxford scientists have developed a system based on ‘frustrated Lewis pair’ chemistry which is capable of selective nitrous oxide sensing with a simple, visible colour change output.
Nitrous oxide is a powerful greenhouse gas with 300 times the heat capacity compared with carbon dioxide. Monitoring nitrous oxide, both over large areas and from industrial emissions, is crucial and new technologies to address detection are needed.
The use of nitrous oxide within the healthcare industry also results in a need for monitoring the exposure to employees and patients from a health and safety perspective. Existing techniques for this are expensive and often do not provide “live” data on exposure.
New chemical entities
Oxford scientists have developed a novel class of chemicals with the ability to reversibly bind nitrous oxide, which are the first small molecules described. The colour change resulting from nitrous oxide binding allows for simple monitoring of exposure.
The ability of the molecules are not limited to nitrous oxide detection and several other applications have been identified or are being tested
- Activation of carbon-hydrogen bonds – demonstrated under mild conditions with phenylacetylene
- Hydrogenation – reversible hydrogen activation/storage demonstrated at room temperature
A patent application protecting key new chemical entities and a range of applications has been filed.
Molecules have been tested and conditions for nitrous oxide capture and release determined. Work to optimise colour change and maximise sensitivity is ongoing.
Oxford University Innovation would like to talk to companies interested in developing a sensor based on this novel class of chemicals.
about this technology