QCM chemical sensor based on ZnO colloid spheres for the alcohols

ZnO colloid spheres with the size below 100 nm were coated on quartz crystal microbalance (QCM) by the self-assembly method. The device exhibits excellent chemical sensing properties in methanol, ethanol, and isopropanol vapor. The kinetics of adsorption-desorption and mechanism of adsorption with different alcohols were studied. The results show that the concentration of analyte vapor affects on the chemical sensitivity of QCM sensor based on ZnO colloid spheres. The adsorption-desorption model is dependent on the type of analytes. Methanol and ethanol molecules adsorb on the ZnO surface much more easily than isopropanol molecules.