Potentials and limitations of a porphyrin-based AT-cut resonator for sensing applications

Acoustic sensors are generally known as high-resolution mass-sensitive transducers. They are composed of piezoelectric crystal plus at least one layer of organic matter to improve chemical sensitivity. The acoustic properties, resumed in the acoustic load impedance, can be exploited by measuring the electric parameters of an equivalent circuit. Some sensing results of a thickness shear mode resonator coated by increasing amounts of a porphyrin solid film have been studied and compared with the performances of the device (quality factor, impedance, motional parameters) to exploit the capabilities and the limitations of a porphyrin-based acoustic chemical sensor.