Magnetic titania-silica composite-Polypyrrole core-shell spheres and their high sensitivity toward hydrogen peroxide as electrochemical sensor

► A novel core-shell sphere with unique structures and compositions was prepared. ► Fe2O3 and TiO2 in FTS particles have synergetic interaction with PPy coatings. ► The spheres show good electrocatalytic activity toward the reduction of H2O2. ► We provide a concept for preparation of new structural function materials.