To enhance the efficacy of Surface-enhanced Raman spectroscopy (SERS), noble metal nanoparticles (NMNPs) can be organized onto three-dimensional (3D) hierarchical nanostructures. This study involved constructing a 3D solid SERS substrate by layering Au-Ag core-satellite nanoparticle monolayer films (MF) on a polystyrene sphere (PS) array, termed Au-Ag core-satellite NPs-MF-PS. Optimizing the PS size was essential to maximize SERS substrate activity, with the 500 nm PS providing the best SERS enhancement factor of 1.03 × 10