Enzyme Mediated Encapsulation of Gold Nanoparticles by Polyaniline Nanoshell

In this contribution we describe the formation of gold nanoparticles (AuNP)and polyaniline (PANI) AuNP-PANI nanocomposite via in situ enzymaticpolymerization. The method consists of electrostatic adsorption of aniliniummonomers on AuNPs citrate stabilized surface of 50 nm diameters, followedby oxidation with horseradish peroxidase (HRP) enzyme and its cofactorH2O2. All reaction steps were monitored by UV-Vis-NIR spectroscopy includ-ing in situ detection of the polymerization process. UV-Vis-NIR, Cyclicvoltammetry (CV) and surface enhanced Raman scattering (SERS) measure-ments supported the formation of a nanoshell of PANI on the AuNP core. Two templates for anilinium assembly were compared revealing a strongdependence of the enzymatic kinetics on the template. The kinetic study hadshown that the rigid template of the AuNP contributes to higher reaction rateon the AuNP compared with the more flexible polyanion template. The mildreaction condition enables an easy and precise method for obtaining PANInano-shell on anionic templates for advanced bioelectronic applications