High-sensitivity detection of acetaldehyde

A set of sensors based on nanostructured single and mixed metal oxides has been prepared and employed in acetaldehyde detection within 0.1–10 ppm, this range being useful for many applications. Electrical characterization has been performed in laboratory at several working temperatures, in order to obtain the optimal operating condition. ZnO working within 450–550 °C, was found to best respond to acetaldehyde. The response vs. concentration curves for all the sensors was a power law with an exponent of 0.5, compatible with the oxidation of acetaldehyde catalyzed by the surface. A decay in the sensor response to acetaldehyde due to humidity was observed and discussed.