1：Experimental Design and Method Selection:

The study involved designing and synthesizing a novel boronic acid derivative (IOPBA) for fluorescence sensing. Theoretical predictions using density functional theory (DFT) calculations were employed to understand molecular conformations and UV spectra. Fluorescence spectroscopy was used to monitor sensing behavior.

2：Sample Selection and Data Sources:

The probe was tested in 0.2 M HEPES buffer solution at pH 7.4 with 2 vol% DMSO. Real water samples (river, tap, pond, industrial effluent) were collected near the Korea Institute of Science and Technology. HeLa cells were used for bioimaging studies.

3：2 M HEPES buffer solution at pH 4 with 2 vol% DMSO. Real water samples (river, tap, pond, industrial effluent) were collected near the Korea Institute of Science and Technology. HeLa cells were used for bioimaging studies. List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: Instruments included UV-Vis spectrophotometer (S-3100, Sinco), fluorescence spectrometer (PerkinElmer LS-45), NMR spectrometer (Bruker Avance 400 MHz), HR-LC-MS (HR-Mass-Synapt G2), pH meter (HI 2210, Hanna Instruments), microplate reader (SpectraMax M2, Molecular Devices), confocal laser scanning microscope (LSM 700, Carl Zeiss). Chemicals included various ions from Accustandard, cell culture materials from Sigma-Aldrich, and solvents from Daejung Chemicals.

4：Experimental Procedures and Operational Workflow:

Synthesis of IOPBA via reaction of 4-boronobenzoic acid with CDI and N'-hydroxy-4-(4,5-diphenyl-1H-imidazol-2-yl)benzamidine. Spectroscopy measurements involved titrating Fe3+ and F? into probe solutions and recording fluorescence changes. Cell culture involved incubating HeLa cells with IOPBA, Fe3+, and F?, followed by imaging.

5：Data Analysis Methods:

LOD calculated using LOD = 3s_b/m from fluorescence titration curves. Binding constants determined using log(F0 ? F)/F = logKA + n log[Q]. Stoichiometry assessed via Job's plot method. Cytotoxicity evaluated with MTT assay.