Functionalisation of polyaniline nanomaterials for amperometric biosensing

This chapter summarizes some procedures for intrinsic functionalization, doping and preparation, analysis and biosensor applications of polyaniline nano-composite materials. Details of the synthesis of four novel nanostructured polymeric composites formed with pristine or substituted polyanilines and sulfonated polyanion, as well as their microscopy, spectroscopy, electrochemistry and multifunctional properties in enzyme electrodes, are presented. In the case of the pristine polyaniline (PANI) and poly(dimethoxy aniline) (PDMA), the polyelectrolyte dopants used were polyvinyl sulfonate (PVS) and polystyrene sulfonic acid (PSS). No dopant was used in conjunction with poly(8-anilino naphthalene sulfonic acid) (PANSA)-a self-doping conducting polymer. A final section deals with the application of the resulting nanocomposites as enzyme-immobilization and conducting platforms in amperometric biosensors involving two oxidoreductase enzymes (horseradish peroxidase and cytochrome P450-2D6). The analytical performances of the resulting biosensors in batch operation mode with regard to their responses to standard samples of selected clinical and environmental analytes, including drugs (e.g. sertraline and fluoxetine), hydrogen peroxide (a strategic biomedical analyte) and some pesticides (e.g., glufosinate and glyphosate) are described. The chapter also demonstrates the application of cyclic voltammetry, scanning electron microscopy, uv-visible spectroscopy and infrared spectroscopy in the development and analysis of biosensors based on functionalized polyaniline nanomaterials.