A ppb level, miniaturized fast response amperometric nitric oxide sensor for asthma diagnostics

This paper reports on a novel miniaturized MEMS-based amperometric nitric oxide sensor that is suitable for a point of care testing device for asthma. The novelty lies in the combination of a high surface area microporous structured electrode, nano-structured Nafion that is coated on the side walls of the micropores, and liquid electrolyte. This combination allows detection of very low concentration (parts-per-billion) gas, has a high sensitivity of 4 μA/ppm/cm² and has both a response and a recovery time of 6 s. The sensor is integrated with a PCB potentiostat to form a complete measuring module. The limit of detection of this sensor was estimated to be 0.3 ppb.