1：Experimental Design and Method Selection:

A solvothermal method was used to synthesize β-NaGdF4:Yb,Er,X% Lu UCNPs with varying Lu3+ doping concentrations. The method was adapted from literature to control phase and morphology. Ligand exchange with HS-PEG2000-NH2 was performed for biocompatibility.

2：Sample Selection and Data Sources:

Nanoparticles with Lu3+ doping levels of 0, 1, 2.5, 4, 6, and 7.5 mol% were prepared. HepG-2 cells and athymic nude mice were used for in vitro and in vivo studies.

3：5, 4, 6, and 5 mol% were prepared. HepG-2 cells and athymic nude mice were used for in vitro and in vivo studies. List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: Rare earth chlorides (YbCl3·6H2O, ErCl3·6H2O, LuCl3·6H2O, GdCl3·6H2O, EuCl3·6H2O), NaOH, NH4F, methanol, cyclohexane, 1-octadecene, oleic acid, HS-PEG2000-NH2, dichloromethane. Equipment includes D/Max-3c diffractometer, JEOL JEM-2100 TEM, Tecnai G2 F20 STEM, AXIS ULTRA XPS spectrometer, Hitachi F-7000 spectrophotometer, 980 nm laser diode, SPEX 1000 M monochromator, DPO4104B oscilloscope, Spectra Max M5 microplate spectrophotometer, Leica TCS SP5 Confocal Microscope, micro-CT scanner.

4：Experimental Procedures and Operational Workflow:

Synthesis involved mixing reagents, heating under argon, precipitation, and centrifugation. Surface modification was done via ligand exchange in dichloromethane. Characterization included XRD, TEM, XPS, UCL spectroscopy, time-decay measurements. Cytotoxicity was assessed using MTT assay. In vitro imaging used confocal microscopy with staining. In vivo CT imaging involved intravenous or intratumoral injection and scanning at intervals.

5：Data Analysis Methods:

XRD data analyzed for phase and lattice changes. UCL spectra analyzed for intensity changes. Cytotoxicity data analyzed using fluorescence intensity measurements. CT images reconstructed using Microview software.