Synthesis of polyaniline catalyzed by soybean peroxidase immobilized in halloysite nanotubes

C. Alvarado-Canché, J. López-Martínez, J. Romero-García, A. Ledezma-Pérez, A. De León-Santillán, C. Gallardo-Vega
Centro de Investigación en Química Aplicada,

Keywords: polyaniline, soybean peroxidase, halloysite nanotubes, enzymatic


Polyaniline is one of the most extended studied conducting polymer because of its simple synthesis, low cost, high conductivity and excellent environmental stability. Synthesis of this inherently conducting polymer can be carried by several methods, being chemical synthesis the most widely reported. However, this method imposes severe limitation because the use of oxidant molecules to initiate the polymerization, those compounds have the potential to be degraded in the air and in some cases anion species and salts are generated as by-products. These unwanted by-products are contaminants that must be eliminated because they interfere with the doping process. Recently, a versatile approach has been address to polymerize aniline using less harmful and drastic reaction media. One of them is the enzymatic polymerization, using well-known oxidative enzymes such as horseradish and soybean peroxidases, which can be activated in an aqueous medium by common oxidizing agents. Halloysite nanotubes, are natural porous inorganic nanostructures that have been used as a nano-reactors for the immobilization of a good number of enzymes. Here, we report the polymerization of aniline using soybean peroxidase immobilized in halloysite nanotubes. The obtained material was characterized by several techniques, included UV-vis, FTIR spectroscopy, TGA and TEM microscopy.