Physicists Developing Graphene-Based Gas Sensor That Could Detect Air Pollutants

Physicists Developing Graphene-Based Gas Sensor That Could Detect Air Pollutants - Electronics Graphene Sensors Special
A graphene-based sensor. Photo credit: Lauri Kulpsood

Physicists at the University of Tartu are working on an artificial nose based on . The device could lead to a new way of monitoring air pollution levels. 

From the UT Blog, “Raivo Jaaniso, the leader of the sensor technologies work group at the Institute of Physics at the University of Tartu, says that as a part of the major European Union project Graphene Flagship, he and his colleagues have set an aim to develop a graphene-based sensor chip of that nature. Their first goal is building a ‘nose’ that could observe the quality of air.”

Graphene is a suitable base material for building chemical sensors: when the molecules from the surrounding air are attached to graphene, its electrical properties abruptly change, which is easy to detect. However, such can be made highly sensitive and selective only by “writing” on graphene with various functional groups or molecules. These “bound-up” additional molecules turn usual graphene layers into delicate sensors that could detect a variety of compounds in the air – from the exhaust gases of vehicles to poisonous ammonia.

UT Blog reports “Ideally, a one-square-millimetre-wide sensor in phones, based on graphene, could measure toxic compounds in the air in real time. Further developments on the sensor would include apps helping us choose healthier daily routes. That’s what the material scientists are already working on in their lab. The prototype of a sensor that responds to exhaust gases from a vehicle, such as NO2, has already been produced and is available in the lab. Recently, a paper on successes in producing ammonia sensors with a similar technology was published. However, it might still take a couple of years until a tool/app suitable for users is fully developed.” 

The parameters of artificial noses existing thus far (the number of sensitive elements, their sensitivity, stability, cost, and size) are not nearly sufficient for real use or point-of-care testing using a smart device. Still, such a nose could potentially fit in a small, portable device – the great future challenge for nano- and microsensor developers.

Source: Randel KreitsbergUT Blog 

Publication Journal: Graphene functionalised by laser-ablated V2O5 for a highly sensitive NH3 sensor, Beilstien Journal of Nanotechnology, 2017, doi: 10.3762/bjnano.8.61

 

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