1：Experimental Design and Method Selection:

The study involved the synthesis of Ag2S QDs and Er3+-doped LNPs, followed by the construction of a QD-sensitized LNP system through metal-affinity interactions. The energy transfer from QDs to LNPs was investigated to enhance NIR-II luminescence.

2：Sample Selection and Data Sources:

Ag2S QDs and Er3+-doped LNPs were synthesized and characterized. The NIR-II luminescence was measured under 808 nm laser excitation.

3：List of Experimental Equipment and Materials:

Transmission electron microscopy (TEM), UV-vis-NIR absorption spectra, NIR-II fluorescence spectra, X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), inductively coupled plasma mass spectrometry (ICP-MS), Fourier-transform infrared (FT-IR) spectra, and fluorescence imaging systems were used.

4：Experimental Procedures and Operational Workflow:

The synthesis of Ag2S QDs and LNPs, their functionalization, and the construction of the QD-sensitized LNP system were detailed. The photostability and in vivo imaging capabilities were evaluated.

5：Data Analysis Methods:

The luminescence enhancement was quantified, and the energy transfer mechanism was analyzed using spectral overlap and lifetime measurements.