Detection of CO2 in solution with a Pt–NiO solid-state sensor

A metal insulator semiconductor field effect transistor (MISFET)-type sensor for the detection of CO2 dissolved in aqueous solution is presented. This all-solid-state device is based on a Pt–NiO thin film as active sensing material on the top of a gate electrode. The fabrication of the sensor is described and its performance is characterized. In particular the transient characteristics and response curves at different biases VRS versus the amount of dissolved CO2 are presented. The sensor shows a linear response to the logarithm of the concentration of dissolved CO2 at room temperature.

Response curves of ΔVRS from MISFET-based sensors with NiO–Pt thin film to different CO2 concentrations. (a) Variable voltage VDS, constant temperature T; (b) constant voltage VDS, variable temperature T.Figure optionsDownload high-quality image (63 K)Download as PowerPoint slide