This study proposes a facile and general method for fabricating a wide range of high-performance SiO2@Au core–shell nanoparticles (NPs). The thicknesses of Au shells can be easily controlled, and the process of Au shell formation was completed within 5 min through sonication. The fabricated SiO2@Au NPs with highly uniform size and SERS activity could be ideal SERS tags for SERS-based immunoassay.
