Selective Recognition of Chloroacetic Acids by Imprinted Polyaniline Film

A novel conductive imprinted polyaniline (PAN) film is prepared by adding template during the PAN film preparation. Monochloroacetic acid (MCA) and trichloroacetic acid (TCA) were used as templates. The conductivity of imprinted PAN films was measured by the four-point probe method. The conductivity changes of imprinted PAN films were compared to reference PAN reflecting the MCA and TCA specific sites on the surface of PAN films. The conductivities were linearly dependent on the template concentrations, and linear calibration curves were obtained in the range 1-30 and 1-40 ppm of the MCA and TCA, respectively. Excellent method reproducibility (standard deviation 0.04 S/cm(-1)) was observed for the determination of 15 ppm MCA. The effect of various factors on preparation, properties, and recognition effects of the imprinted PAN films was investigated. The best electrical and mechanical properties were obtained with 7 x 10(-4) mmol MCA as a template and doping agent. The measurements are carried out under room temperature, and the maximum conductivities are reached after about 10 and 20 min for reference and imprinted PAN film, respectively. Selectivity experiments were carried out with standard MCA, TCA, and five analogs (dichloro-, dibromo-, and monobromoacetic acid) in water. The results exhibited a good selectivity for the templates compared to structurally related compounds. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 121: 292-298, 2011