1：Experimental Design and Method Selection:

The study involved designing and synthesizing a benzothiazole-derived cyanine probe (Cy-SN) for specific reaction with peroxynitrite (ONOO-) through oxidative cleavage of conjugated C=C double bonds, leading to fluorescence quenching and color change. Methods included UV-Vis absorption spectroscopy, fluorescence spectroscopy, mass spectrometry, and confocal microscopy for imaging.

2：Sample Selection and Data Sources:

Peroxynitrite was generated from H2O2 and NaNO2; other reactive species were prepared from commercial supplies. Murine RAW264.7 macrophage cells were used for cytotoxicity tests and imaging studies.

3：7 macrophage cells were used for cytotoxicity tests and imaging studies. List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: Equipment included Pekin-Elmer LS-55 luminescence spectrophotometer, Shimadzu UV-2550 spectrometer, Varian Mercury-400 NMR spectrometer, Agilent Technologies 6224 TOF LC/MS mass spectrometer, pHS-3C pH meter, laser Confocal Microscopy (OBSERVER Z1, ZEISS), and Canon 350D digital camera. Materials included various chemicals from Aladdin, Sigma Aldrich, and Sinopharm Chemical Reagent Co. Ltd.

4：Experimental Procedures and Operational Workflow:

Synthesis of Cy-SN probe, preparation of ONOO- and other species, cytotoxicity testing via MTT assay, fluorescence and absorption measurements, mass spectrometry analysis, and confocal imaging of cells treated with probes and ONOO- donors or stimulants.

5：Data Analysis Methods:

Fluorescence intensity changes were analyzed for linear relationships and detection limits. Mass spectrometry data confirmed reaction products. Statistical analysis included standard deviations from triplicate measurements.