Metal Oxide Semiconductor Sensors for Acetone Detection with Hot Wire Type Structure

We present an affordable metal oxide semiconductor sensor suitable for acetone detection below 1 ppm. The sensor has a unique structure, in which components are only bare essentials: a coil of noble metal for both heating and measuring, a semiconductor bead for detecting acetone, and a catalytic overlayer for removing interference gases. The sensor exhibited good sensitivity to acetone together with selectivity over ethanol and hydrogen. These properties were retained for more than two years in a laboratory environment, demonstrating excellent long-term stability of the sensor.