Synthesis and characterization of dendritic polypyrrole silver nanocomposite and its application as a new urea biosensor

ABSTRACT Polypyrrole and its silver nanocomposite were electrochemically synthesized from aqueous solutions containing pyrrole, potassium chloride (KCl) (system A); pyrrole, KCl, and an anionic surfactant sodium dodecyl sulphate (NaDS) (system B); and pyrrole, silver nitrate, NaDS (system C). Compact and dendritic patterns were observed depending on experimental conditions. The aggregates were characterized by powder X‐ray diffraction, energy‐dispersive X‐ray spectroscopy, scanning electron microscopy, high resolution transmission electron microscopic (HRTEM), and thermal studies (TG/DTG). HRTEM studies indicate that the particle size of PPy‐Ag nanocomposite is ∼30 nm. TG studies revealed that systems B and C, have different thermal behavior. Potassium ion selective electrodes were constructed using systems A, B, and C. The electrode prepared with PPy‐Ag nanocomposite showed nernstian behavior with maximum slope of 57 mV. NH4+ ion‐selective electrode was also constructed for this system based on nonactin‐impregnated PVC matrix membrane. Urease enzyme was immobilized at the surface of as made NH4+ ion‐selective electrode to develop urea biosensor showing good detection limit. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45705.