1：Experimental Design and Method Selection:

BP QDs were prepared by pyrolysis method and used as fluorescent probes for trace metal ions. The methodology included the synthesis of BP QDs, their characterization, and the evaluation of their fluorescence quenching in the presence of metal ions.

2：Sample Selection and Data Sources:

BP QDs were synthesized from BP crystals. Metal ions such as Hg2+ and Cu2+ were selected for detection in aqueous and organic solutions.

3：List of Experimental Equipment and Materials:

Equipment included SEM, TEM, HRTEM, XRD, Raman spectrometer, AFM, UV–vis spectrophotometer, FT-IR spectrometer, fluorescence spectrometer, and XPS. Materials included NMP, NaOH, BP crystals, and standard solutions of metal ions.

4：Experimental Procedures and Operational Workflow:

BP QDs were synthesized, characterized, and then mixed with metal ions of different concentrations. The fluorescence intensity was measured using a 450 nm laser.

5：Data Analysis Methods:

The fluorescence quenching was analyzed using PL lifetime tests and XPS. The adsorption energy and electronic structure of BP QDs after adsorption of metal ions were calculated using density functional theory.