Multifunctional polymers for sensing applications

Multifunctional polymers of poly(amidoamine) structure were proposed as sensor coatings for the detection of sulfur dioxide. They were amorphous rubber-like materials, and therefore characterized by good conformational dynamics. This property is particularly significant in view of applications in the sensors field, because it favors diffusion of the analyte's molecules through the coating layer. The electronic devices used for evaluating the extent of SO2 sorption by the poly(amidoamine) coatings were gravimetric resonant sensors based on quartz crystal microbalances. The polymeric coatings were in the form of thin films obtained by casting procedures from dilute methanol solutions. All experiments were performed under controlled humidity and temperature environments. All materials were sensitive to SO2 variations of the order of ppm. The response times were in the range of 3-4 min. The dependence of SO2 sorption by poly(amidoamine) films on moisture content and film thickness was investigated.