Comparative analysis of sensor responses of thin conducting polymer films to organic solvent vapors

A comparative analysis of responses of thin films of various conducting polymers (polyaniline, polypyrrole and poly-3-methylthiophene) to the vapors of polar as well as low- and nonpolar organic solvents was performed. Conductivity measurements, infra-red and electron paramagnetic resonance spectroscopy were used to characterize responses of the polymer films doped with different dopants. Main physical and chemical factors which define the magnitude of the response to the studied analytes were determined. It was shown that the differences in response of conducting polymer films are conditioned by the influence of chemical structure of the polymer and its dopant, and also by different nature of their doping.