1：Experimental Design and Method Selection:

The study involved the synthesis of spherical gold nanoparticles (AuNPs) using the Turkevich method and coating them with sodium silicate stock solution (Na2SiO3). The effect of different rates of SiO2 and ethanol on the SPR position was studied using UV–Vis absorption spectroscopy.

2：3). The effect of different rates of SiO2 and ethanol on the SPR position was studied using UV–Vis absorption spectroscopy. Sample Selection and Data Sources:

2. Sample Selection and Data Sources: Gold nanoparticles were synthesized and coated with varying concentrations of SiO2 and ethanol. The samples were then analyzed using UV–Vis spectroscopy.

3：List of Experimental Equipment and Materials:

Chloroauric acid (HAuCl4), Trisodium citrate dihydrate (Na3C6H5O7), Sodium silicate stock solution (Na2SiO3), Sodium hydroxide (NaOH), Ethanol (C2H5OH), UV–Vis spectrophotometer.

4：Experimental Procedures and Operational Workflow:

Gold nanoparticles were synthesized by heating a solution of chloroauric acid and adding trisodium citrate dihydrate. The nanoparticles were then coated with sodium silicate solution at different concentrations and ethanol rates. The coated nanoparticles were analyzed using UV–Vis spectroscopy to observe the SPR shift.

5：Data Analysis Methods:

The UV–Vis spectra were analyzed to determine the SPR peak positions and shifts.