Mist Sensing of Formaldehyde and Toluene with Quartz Crystal Microbalance Coated with Lipid Film using Ultrasonic Atomizer

An analytical technique using AT-cut 9 MHz quartz crystal microbalance (QCM) mist sensors coated with lipid film [dimethyl didodecylammonium poly(styrene sulfonate) (2C12N+/PSS-)] was investigated. The mist sensors coated with lipid films had a different sensitivity to volatile organic compounds (VOCs), whose fine mists were produced by ultrasonic vibration using an atomizer. The VOCs used for mists are formaldehyde and toluene. The frequency shift of the sensor coated with the film is significantly higher than that of the sensor without the films. The surface morphology of the sensor coated with the films is more rugged than that of the sensor without the films. The diversity of surface structure contributes to the improvement of QCM sensitivity.