Response of a SAW Sensor Array based on Nanoparticles for Measuring Ammonia in the Environment

Four surface acoustic waves (SAW) sensors based on sensitive layers of Fe2O3 nanoparticles, pure and combined with noble metals nanoparticles, composed an array sensor to measure ammonia in the environment. The sensor array was tested with nanostructured sensitive layers, which detected the changes of the elastic properties induced by ammonia interaction. The sensor with pure Fe2O3 nanoparticles exposed to 50 ppm of ammonia showed no significant effect, however the sensors with Fe2O3 nanoparticles combined with Au, Pt and Pd nanoparticles responded to these concentrations of this gas, which is so dangerous for the environment and the health, with a high sensitivity.