1：Experimental Design and Method Selection:

The study involves theoretical and numerical investigation using a model based on Helmholtz's equations and Lorenz-Mie theory to analyze whispering-gallery-modes (WGMs) in a triple-layer-coated microsphere. Finite-difference time-domain (FDTD) method is employed for simulations.

2：Sample Selection and Data Sources:

The microsphere is modeled with specific refractive indices (n1=1.452 for body, n0=1 for medium, nA=nC=3.58 for high-RI layers, nB=1.452 for low-RI layer) and thicknesses (dA=dC=200 nm, dB varied from 100 to 600 nm). Nanoparticles are simplified as circles with diameter d and refractive index n

3：452 for body, n0=1 for medium, nA=nC=58 for high-RI layers, nB=452 for low-RI layer) and thicknesses (dA=dC=200 nm, dB varied from 100 to 600 nm). Nanoparticles are simplified as circles with diameter d and refractive index nList of Experimental Equipment and Materials:

2. 3. List of Experimental Equipment and Materials: A fiber waveguide (width 300 nm), laser, photodetector, and microsphere coated with silicon and silica layers (fabricated via Sol-Gel technique or radio frequency sputtering method) are used in the detection system.

4：Experimental Procedures and Operational Workflow:

The system is set up with a gap distance of 150 nm between waveguide and microsphere for phase matching. Light is emitted and received to excite WGMs, and resonance wavelength shifts (RWS) are measured before and after nanoparticle attachment.

5：Data Analysis Methods:

Numerical calculations and FDTD simulations are used to compute field distributions, resonance wavelengths, and RWS. Perturbation theory is applied to derive RWS equations.