Effects of surfactants on the characteristics and biosensing properties of polyaniline

To investigate the effects of surfactants on the properties of polyaniline (PANI), a series of PANIs was synthesized in the presence of surfactants by chemical polymerization of aniline in an acidic medium, using (NH4)(2)S2O8 as oxidant. Three types of surfactant were used: (i) non-ionic poly(ethylene oxide) (20) sorbitan monolaurate (Tween 20) and poly(ethylene oxide) (20) sorbitan monopalmitate (Tween 40); (ii) cationic (1-tetradecyl) trimethylammonium bromide; and (iii) anionic sodium 1-dodecanesulfonate and sodium 1-pentanesulfonate. The structural, morphological and thermal properties of the various samples were characterized using Fourier transform infrared and UV-visible spectroscopy, scanning electron microscopy and thermogravimetric analysis. Calorimetry was used to compare enthalpy changes during polymerization. The electrochemical and glucose biosensor properties of the PANIs were investigated using cyclic voltammetry and amperometric measurements. PANI-Tween 20 and PANI-Tween 40 were found to be good for immobilization of glucose oxidase enzymes and potential candidates for use in glucose biosensing. (C) 2010 Society of Chemical Industry