Graphene-Based NO₂ Detectors could be Cheap and efficient. NO₂ sensors measure changes in graphene’s electrical resistance to record pollutant levels.
Graphene Flagship partners at the National Physical Laboratory, UK, and Chalmers University of Technology, Sweden, alongside colleagues at the Advanced Institute of Technology, UK, Royal Holloway University, UK, and Linköping University, Sweden, have created a low-cost, low-energy consuming NO2 sensor that measures NO2 levels in real-time – and it could help to visualize pollution in urban areas.
NO2 gas is produced by burning fossil fuels, and it can cause airway inflammation, leading to breathing problems and even asthma attacks. The European Union and UK Parliament have introduced legislation to regulate the amount of NO2 in the air – but significant portions of the population are exposed to NO2 levels above this limit, so experts are calling for new ways to monitor pollutant levels.
The two usual methods to monitor air pollution are optical laser techniques, such as chemiluminescence, but this requires large and expensive lab equipment – and metal oxide detectors, which are small but lack sensitivity. Neither of these are good enough for large scale, continuous NO2 monitoring, so Graphene Flagship researchers are working on new, innovative sensing devices.
Christos Melios, from the National Physical Laboratory and the Advanced Institute of Technology, UK, and colleagues have now developed a graphene-based NO2 detector that reports pollutant levels based on changes in its electrical resistance. They grew graphene on silicon carbide, etched it into an appropriate shape and fused it to a detector chip using metal wires. When NO2 from the air is physically absorbed by the graphene layer, the resistance of the graphene changes, which produces a recordable signal.
Source: Printed Electronics