1：Experimental Design and Method Selection:

The study employed a dual quenching strategy (ESIPT inhibited quenching and PET quenching) to design probe 1 for detecting H2Sn. The fluorophore dye 2 was synthesized and characterized, and probe 1 was created by attaching a recognition moiety. Spectroscopic studies, selectivity tests, kinetic studies, pH effect evaluations, cell imaging, and zebrafish imaging were conducted.

2：Sample Selection and Data Sources:

Samples included probe 1 and dye 2 solutions, various analytes (e.g., Na2S2, Na2S, etc.), A549 cells, and zebrafish embryos. Data were acquired through UV-Vis and fluorescence spectroscopy, mass spectrometry, NMR, and confocal microscopy.

3：List of Experimental Equipment and Materials:

Equipment included Shimadzu UV-2450 spectrophotometer, Shimadzu RF5301PC spectrophotometer, Waters Xevo G2-S QTof mass spectrometer, BRUKER 400 spectrometer, Zeiss LSM710 microscope, PHS-3C pH meter. Materials included reagents from commercial sources, TLC plates, silica gel, and synthesized compounds.

4：Experimental Procedures and Operational Workflow:

Synthesis of dye 2 and probe 1 involved specific chemical reactions. Spectral studies involved mixing probe stock with analytes in PBS buffer. Cell assays included incubating A549 cells with probe and H2Sn. Zebrafish imaging involved treating embryos with H2Sn and probe.

5：Data Analysis Methods:

Fluorescence intensities were measured and analyzed for linear relationships, detection limits, and selectivity. Statistical analysis included signal-to-noise ratio calculations for detection limit.