tEfficient, scalable, and cost-effective self-assembly of Au nanoparticles (NPs) into close-packed arrays onthe surfaces of thiol-functionalized resin spheres under mild conditions was demonstrated. The resultingAu NPs–resin spheres possessed a structure in which the densely packed Au NPs monolayer and theresin bead are the shell and the core, respectively. Each Au NPs–resin sphere could be used as a surface-enhanced Raman scattering (SERS) substrate with high SERS-enhancing capacity and reproducibility. TheSERS enhancement factor (EF) was estimated at 109–1011by using thiophenol as the probe. The spatialand sphere-to-sphere variations in SERS EF were