1：Experimental Design and Method Selection:

The study employed colloidal lithography using polystyrene spheres as masks. Electrostatic interactions were exploited for particle absorption, with strategies involving salt concentration and absorption time variations. Methods included functionalization of substrates, particle assembly, and nanostructure fabrication via metal deposition and etching.

2：Sample Selection and Data Sources:

Glass substrates were used, and polystyrene spheres of diameters 80 nm and 500 nm were selected. Samples were prepared with different NaCl concentrations, particle concentrations, and absorption times as detailed in Table

3：List of Experimental Equipment and Materials:

Equipment included SEM (Carl Zeiss), UV–visible spectrophotometer (Cary500), magneto-optical Kerr effect setup with He–Ne laser and lock-in amplifier, and COMSOL Multiphysics for simulations. Materials included glass substrates, polystyrene spheres, polyelectrolytes (PDDA, PSS, PAH), NaCl, gold, cobalt, and chemicals for cleaning and functionalization.

4：Experimental Procedures and Operational Workflow:

Substrates were cleaned and functionalized with polyelectrolyte layers. Particles were assembled by immersion in suspensions with controlled parameters, followed by rinsing, heating, drying, and nanostructure fabrication via metal deposition and etching. SEM imaging and optical/magnetic characterization were performed.

5：Data Analysis Methods:

ImageJ software was used for SEM image analysis to compute coverage and radial distribution functions. Absorbance spectra and MOKE hysteresis loops were analyzed, and numerical modeling in COMSOL was used for optical response simulations.