Silver nanoparticle-decorated polyaniline nanorods (AgNPs-PANINRs) and silver nanoparticle-decorated polyaniline nanotubes (AgNPs-PANINTs) composites were prepared through a one-step modified methods by immobilizing a mixture of AgNO3, aniline and ammonium per sulfate (APS) as an oxidant without adding any extra acids, templates or surface modifiers. The composites were characterized by using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The reactivity of the prepared composites towards hydrogen peroxide (H2O2) was analyzed using cyclic voltammetry and chronoamperometry. The AgNPs-PANINRs composite exhibits better electrochemical performance than the AgNPs-PANINTs composite due to higher content of silver nanoparticle (AgNPs). The sensor has a fast amperometric response time which less than 3 s. The detection limit and limit of quantification (S/N = 3) of two linear range (low and high concentration of H2O2) are estimated as 0.13 mu M and 0.45 mu M and 0.33 mu M and 1.12 mu M, respectively. (C) 2015 The Electrochemical Society. All rights reserved.