Architecture of poly(o-phenylenediamine)-Ag nanoparticle composites for a hydrogen peroxide sensor

A novel strategy to fabricate a hydrogen peroxide (H2O2) sensor was developed by electrodepositing Ag nanoparticles (AgNPs) on a poly(o-phenylenediamine) (PoPD) film modified glassy carbon electrode (GCE). Firstly, the o-phenylenediamine was polymerized on a GCE by potential cycling to produce PoPD film. Then the AgNPs were electrodeposited on the PoPD film to form AgNPs/PoPD/GCE. The morphology of the electropolymerized PoPD film and the electrodeposited AgNPs were characterized by atomic force microscopy. The results showed the PoPD film was porous and the AgNPs dispersed uniformly on the PoPD film. Cylic voltammetry and amperometry were used to evaluate electrocatalytic properties of the AgNPs/PoPD/GCE. The electrode displayed good electrocatalytic activity in the reduction of H2O2 and could be used as a sensor for H2O2 detection. The sensor exhibited fast amperometric response to H2O2 with high selectivity, good reproducibility and stability. The linear range was 6.0 mu M to 67.3 mM with a detection limit of 1.5 mu M. Thus, it is considered to be an ideal candidate for practical application. (C) 2011 Elsevier Ltd. All rights reserved.