Oxygen Plasma Treated RGO Based Resistive Sensor: A Step Towards NH3 Detection from Human Breath

This report presents the impact of oxygen-plasma treatment on reduced graphene oxide (rGO) for ammonia (NH3) sensing ability. Raman and FTIR characterization suggest induction of defects and oxygen functional groups on rGO following the treatment of Oxygen-plasma. Using the material as channel, a two terminal resistive sensor is developed. The sensing response indicates high selectivity towards NH3 and water vapour. In case of water vapour there is recovery of base current along with higher response. Unlike the water vapour, NH3 reduced the current and response is relatively lower. Due to such distinctive features in the sensor response, the selective detection of ammonia through this sensor is proposed. Moreover, this sensor is found to be able to sense low concentration (1–5 ppm) of ammonia, comparable to concentrations observed in human exhaled breath, suggesting its possible implementation in medical diagnostics.