Properties of dendrimer-encapsulated pt nanoparticles doped polypyrrole composite films and their electrocatalytic activity for glucose oxidation

A type of novel electroanalytical sensing nanobiocomposite material was prepared by electropolymerization of pyrrole containing poly(amidoamine) dendrimers-encapsulated platinum nanoparticles (Pt-PAMAM), and glucose oxidase (GOx). The Pt nanoparticles encapsulated in PAMAM are nearly monodisperse with an average diameter of 3 nm, and they provide electrical conductivity. Polypyrrole acts as a polymer backbone to give stable and homogeneous cast thin films, and it also defines the electrical conductivity. Both Polypyrrole and PAMAM can provide a favorable microenvironment to keep the bioactivity of enzymes such as glucose oxidase. The homogeneity of GOx/Pt-PAMAM-PPy nanobiocomposite films was characterized by atomic force microscopy (AFM). Ampero-metric biosensors fabricated with these materials were characterized electrochemically using cyclic voltammetry (CV) I electrochemical impedance spectra (EIS) and amperometric measurements in the presence of hydrogen peroxide or glucose. All those show the resultant biosensor sensitivity was strongly enhanced within the nanobiocomposite film. The optimized glucose biosensor displayed a sensitivity of 164 mu A mM(-1) cm(-1), a linear range of 0.2 to 600 mu M, a detection limit of 10 nM, and a response time of < 3s.