1：Experimental Design and Method Selection:

The nanoprobe 1 was synthesized by mixing Pt(II) metallacycle 2, NIR-II molecular dye 3, and DSPE-mPEG5000 in a 1:1:8 weight ratio. Methods included NMR, ESI-TOF-MS, TEM, DLS, UV/Vis spectroscopy, fluorescence imaging, ICP-MS, cytotoxicity assays, and in vivo studies in mouse models.

2：Sample Selection and Data Sources:

HepG2 cancer cells and L929 normal cells were used for in vitro studies. C57BL/6 mice and HepG2 tumor-bearing nude mice were used for in vivo imaging and therapy evaluation.

3：List of Experimental Equipment and Materials:

Equipment included Bruker 400-MHz NMR spectrometer, Applied Biosystems 4700 MALDI TOF mass spectrometer, PekinElmer Lambda 25 UV-Vis spectrophotometer, NIR-II fluorescence microscope and imaging system from Suzhou NIR-Optics Technologies, Malvern Zetasizer Nano ZS for DLS, Dionex HPLC system, Hitachi TEM system, and ICP-MS. Materials included precursors 4 and 5, dye 3, DSPE-mPEG5000, and cisplatin as control.

4：Experimental Procedures and Operational Workflow:

Synthesis and characterization of rhomboid 2 and dye 3, formation of nanoprobe 1, stability tests in PBS with FBS, photostability tests, in vitro cell imaging and uptake studies using ICP-MS and fluorescence microscopy, in vivo NIR-II imaging of lymphatic system and brain vessels, pharmacokinetics studies, and antitumor efficacy evaluation in tumor-bearing mice with body weight and survival monitoring.

5：Data Analysis Methods:

Data were analyzed using statistical methods for cytotoxicity (MTT assay), fluorescence intensity measurements, ICP-MS for Pt quantification, and imaging analysis for S/N ratios and resolution.