Quartz crystal microbalance odor sensor coated with mixed-thiol-compound sensing film

The selectivity of the quartz crystal microbalance odor sensor is influenced by the sensing film structure. Thiol compounds were used for the sensing film materials. We made and used several mixed sensing films with different film structures. The mixing ratio was varied to produce different film structures. From a comparison of the sensor response properties and the observation of the film structure by AFM, we verified that the different film structures and thus different response properties can be achieved by varying the mixed ratio of the sensing film. This result indicates that the control of the sensing film structure is important for obtaining a sensor with the desired response property. We demonstrated a new method for the deposition of sensing film with a desired response property, using the affinity between odor molecules and sensing film materials in the depositing solution. By using this method, we can easily obtain a sensor with the desired response property.