Metal@dielectric composite nanostructures are of high demand for their vast technological applications. The Stober method, either in its original form or by modification, has been utilized for the fabrication of silica shells over metal, semiconductor, or even dielectric nanostructures, with the aim to protect them from degradation, enhance their biocompatibility, or use them for molecular anchoring. However, the stability of silica shells and the dispersion of core–shell nanostructures remain the main limitations for their efficient applications. Here we demonstrate that utilization of ultrasound during hydrolysis and condensation of the metal–organic silicon precursor in Stober process can produce stable and uniform silica shell layers around gold nanoparticles, enhancing both their stability and dispersion. Through transmission electron microscopy and infrared spectroscopy techniques, we demonstrate that the Au@SiO2 nanoparticles fabricated with ultrasound treatment during silica shell growth contain a...