Synthesis of Ag at SiO₂ yolk-shell nanoparticles for hydrogen peroxide detection

Yolk-shell nanostructures are a potential platform for the application of sensors and detection. In this paper, Ag@SiO₂ yolk-shell nanoparticles (YSNs) were synthesized by a facile "two solvents" impregnation-reduction approach. XRD, SEM, TEM and N₂ adsorption characterization results revealed that the resultant Ag@SiO₂ YSNs possess distinctive structures, such as movable cores, perpendicular mesoporous channels, protective shells and hollow cavities. A nonenzymatic H₂O₂ sensor was constructed using Ag@SiO₂ YSNs as sensing interface. A three-electrode system was used for the measurement. Electrochemical results indicate that the Ag@SiO₂ YSNs modified electrode exhibits outstanding performance toward the H₂O₂ reduction, with a faster amperometric response, a lower detection limit (3.5 μM) and a wider linear range (0.1-15 mM) than that based on Ag@SiO₂ composites, which was synthesized by a direct impregnation method.