The effect of the nature of the dopant on the sensor response of poly(3-methylthiophene) films

The effect of the nature of the dopant on the response of a sensor array based on films of poly(3-methylthiophene) under the influence of various organic solvents was studied. It was established that the electroconductivity of the polymer can both increase and decrease under the influence of the analytes. It was suggested that the main factors determining the magnitude of the response of poly(3-methylthiophene) are the ratio of the number of radical-cationic and dicationic states in the polymer, which depends on the nature of the dopant-anion, and also the polarity of the analyte. It was shown that the polymer has high sensitivity to chloroform vapor, which makes sensor arrays based on poly(3-methylthiophene) selective with respect to this analyte. __________ Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 42, No. 6, pp. 331–338, November–December, 2006.     

Effect of the Nature of the Dopant on the Response of a Sensor Array Based on Polyaniline

The effect of the nature of the dopant on the response of a sensor array based on films of polyaniline (PAn) under the influence of the vapor of various organic solvents was studied. It was established that the main factors determining the magnitude of the response of PAn films are the morphology of the films and the accepting power of the analyte molecules (in the case of "standard" acid dopants) and also the possibility of additional donor–acceptor interaction between the analyte molecules and the dopant (in the case of heteropoly acid dopants). It was shown that with heteropoly acids as dopants of PAn it is possible to increase substantially the selectivity of the response of the sensor array.