1：Experimental Design and Method Selection:

The study involved designing and synthesizing a novel molecule DTE-Pip-Rho 1O, with a focus on its response to Hg2+ ions and UV/vis light. Methods included UV-Vis absorption spectroscopy, fluorescence spectroscopy, HPLC, ESI-MS, NMR, and photoirradiation experiments to study photochromism and FRET mechanisms.

2：Sample Selection and Data Sources:

DTE-Pip-Rho 1O was synthesized and dissolved in CH3OH-H2O (7/3, v/v) solution. Metal ion solutions (e.g., Hg2+, Cu2+) were prepared from inorganic salts in deionized water.

3：List of Experimental Equipment and Materials:

Equipment included a Brucker AM-400 spectrometer for NMR, Agilent 1100 ion trap LC/MS MSD system for MS, Agilent 8453 UV/vis spectrophotometer for UV-Vis spectra, Hitachi F-4600 fluorescence spectrophotometer for fluorescence spectra, WRS-1B melting point apparatus, and Agilent 1260 HPLC system with a ZORBAX SB-C18 column. Chemicals were purchased from Aldrich or J & K Scientific Ltd.

4：Experimental Procedures and Operational Workflow:

Synthesis of compounds 2 and DTE-Pip-Rho 1O was performed via reactions in CH3CN and ethanol, followed by purification. Titration experiments with Hg2+ were conducted to measure absorption and fluorescence changes. Photoirradiation with UV (297 nm) and visible light (>500 nm) was used to study photochromism and fluorescence switching.

5：Data Analysis Methods:

Data were analyzed using standard curves for detection limits (3σ/k method), HPLC for photoconversion ratios, and spectral overlap for FRET analysis.