Amperometric sensors based on Nafion Proton onductor: A comparison between two different structures

In this work the authors propose the development and the characterization of two NO2 amperometric detection systems, based on two different solid state electrochemical sensors. Both sensors have a Nickel Oxide counter electrode, a Graphite working electrode, and Nafion as protonic conductor. The first detection system exploits a two-electrode sensor that presents a satisfactory sensitivity to NO2, a very low cross-response to interfering gases (CO, O2), a short response time, and that requires simple front-end electronics. Nevertheless, the usage of this sensor is limited to the detection of low NO2 concentrations (below 10 ppm). A similar performance can be obtained by a system based on a three-electrode version of the sensor which can be used in a wider NO2 concentration range, but requires a more complex front end electronics.