Nitrogen dioxide (NO2), a gas emitted by industry and traffic, is a major contributor to nitrogen deposition in the Netherlands, alongside ammonia, which is emitted mainly by the agricultural sector. Unfortunately, NO2 is not easy to measure, not on the ground, and certainly not high in the atmosphere. Although there are NO2 meters, these meters also measure a variety of other gases, making the readings unreliable.
KNMI, which measures NO2, would like to take better, more precise measurements than they are able to do at present, says Kouwer. “For their measurements in the atmosphere, they use weather balloons, but the sensors often break down in the process. NO2 is quite easy to measure in a lab situation, so what you actually want is some kind of portable lab setup, which can be placed in one of these weather balloons.”
This will soon be possible, thanks to the NWO-OTP grant. The GELSONDE project brings together a team of materials chemists and sensor specialists who are joining forces to create a new, low-cost, and portable sensor. Kouwer: “In my lab, we are developing the materials and molecules that will make NO2 visible. Think of a fluorescent signalling material in a gel. We are working with Simona Cristescu's group, who are experts in measuring those signals. Our other partners are helping us to build a prototype that we will test in a KNMI weather balloon. Our objective is to be able to deploy our new sensor widely, in business parks, at events, and high in the atmosphere, so that we can accurately measure NO2 concentrations anywhere.”
The grant makes it possible to fund a PhD candidate for Kouwer's lab and a postdoc for Cristescu's lab. The NO2-signaling gel should be as sensitive and as stable as possible. The process of reading the fluorescent signal from the gel will also be refined further. Kouwer: “Together with our partners, we will use the next four years to create a prototype that is usable in practice, stable, convenient, and affordable. In the process, we will obviously also keep in mind that a similar device could be used to measure other gases than NO2.”
The GELSONDE project partners are:
- Paul Kouwer, Synthetic Organic Chemistry, Radboud University
- Simona Cristescu, Life Science Trace Detection Laboratory, Radboud University
- The Royal Netherlands Meteorological Institute (KNMI)