1：Experimental Design and Method Selection:

A simple method was used to synthesize Ag@NaGdF4:Yb3+, Er3+ core-shell nanostructures, incorporating luminescent, magnetic, and photothermal properties. The design rationale was to create a theranostic nanoagent for bio-imaging and PTT.

2：Sample Selection and Data Sources:

Ag nanoparticles were synthesized using an ethylene glycol method, and core-shell NCs were prepared by encapsulating Ag NPs with NaGdF4:Yb3+, Er3+ NPs. Biological tests used HeLa cells, normal human hepatocytes (7702), and hepatoma cells (7721).

3：1). List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: Chemicals included lanthanide oxides, nitric acid, PVP, ethylene glycol, ethanol, acetone, sodium citrate, sodium fluoride, silver nitrate. Equipment included XRD (Rigaku D/max-RA), SEM (JEOL JSM-610), TEM (JEOL-2010EX), UV-Vis spectrophotometer (Shimadzu UV-2450), fluorescence spectrophotometer (HITACHI F-7000), VSM, laser diodes (980 nm and 808 nm), thermometer (HTC3500C), thermal imaging camera, confocal fluorescence microscopy (Olympus), microplate reader, and CT imaging system (Bruker).

4：Experimental Procedures and Operational Workflow:

Synthesis of Ag NPs and core-shell NCs, characterization via XRD, SEM, TEM, EDS, UV-Vis, UCL spectra, magnetization measurements. Photothermal evaluation with laser irradiation, cytotoxicity assay using MTT, PTT on living cells with FDA/PI staining, UCL imaging with confocal microscopy, CT imaging with Bruker system.

5：Data Analysis Methods:

XRD patterns compared to standard JCPDS cards, SEM and TEM for morphology, EDS for elemental analysis, UV-Vis for absorption, UCL spectra for luminescence, VSM for magnetization, temperature changes recorded, cell viability calculated from absorbance, imaging analyzed qualitatively and quantitatively.