1：Experimental Design and Method Selection:

The probe CP was designed using P-OH as the fluorophore and acryloyl group as the recognition unit, based on Michael addition and intramolecular cyclization mechanisms for selective Cys detection.

2：Sample Selection and Data Sources:

Biologically relevant analytes including Cys, GSH, Hcy, and other amino acids were used; HeLa cells were cultured for cellular imaging.

3：List of Experimental Equipment and Materials:

Instruments included UV-vis spectrometer, fluorescence spectrophotometer, confocal laser scanning microscope, NMR spectrometer, mass spectrometer; materials included chemicals like acryloyl chloride, solvents, and cell culture reagents.

4：Experimental Procedures and Operational Workflow:

Synthesis of CP and P-OH, spectral measurements in PBS-DMSO buffer, time-dependent and titration experiments, selectivity tests, pH effect studies, cytotoxicity assays, and confocal imaging in HeLa cells.

5：Data Analysis Methods:

Fluorescence intensity changes were monitored; detection limit was calculated using DL=3σ/k; statistical analysis for cell viability and imaging quantification.