1：Experimental Design and Method Selection:

The study involved designing a fluorescent probe based on Hg2+-mediated ester hydrolysis. The probe MBPVP was synthesized and its spectral properties were investigated using UV-vis and fluorescence spectroscopy. The mechanism was confirmed through mass spectrometry and NMR analysis.

2：Sample Selection and Data Sources:

The probe MBPVP was synthesized in the laboratory. Metal ion solutions (e.g., Hg2+, Ag+, Cu2+, etc.) were prepared from their chloride or nitrate salts. Real water samples (tap water and Fenhe river water) were spiked with known concentrations of Hg2+ for application testing.

3：List of Experimental Equipment and Materials:

UV-2450 spectrophotometer (Shimadzu), F4500 fluorescence spectrometer (Hitachi), 400 MHz NMR spectrometer, high-resolution mass spectrometer (Bruker Autoflex), chemicals such as 4-hydroxybenzaldehyde, 4-methylpyridine, iodomethane, and various metal salts purchased from Aldrich.

4：Experimental Procedures and Operational Workflow:

Synthesis of MBPVP was carried out via ionization reaction. Spectral experiments were performed in 100% PBS buffer (pH 7.4) at 25°C. Fluorescence titrations, selectivity tests, response time studies, pH effect investigations, and real sample applications were conducted with specific concentrations and conditions as described.

5：4) at 25°C. Fluorescence titrations, selectivity tests, response time studies, pH effect investigations, and real sample applications were conducted with specific concentrations and conditions as described. Data Analysis Methods:

5. Data Analysis Methods: Fluorescence intensity was measured at 520 nm with excitation at 380 nm. Detection limit was calculated using the IUPAC formula (CDL = 3Sb/m). Statistical analysis included recovery and relative standard deviation (RSD) calculations for real sample data.