1：Experimental Design and Method Selection:

The study employs a fluorescence quenching mechanism based on interactions between BSA and gossypol to detect gossypol. BSA-Cu NCs are synthesized and used as fluorescent indicators.

2：Sample Selection and Data Sources:

Real samples include cottonseed meal and oil, prepared according to GB

3：148-Gossypol solutions are prepared by serial dilution. List of Experimental Equipment and Materials:

50 Materials include BSA, H2O2, CuSO4, NaOH, gossypol, glucose, palmitic acid, glycine, and ultra-pure water. Equipment includes a Hitachi F-2500 fluorescence spectrophotometer, Beckman DU-800 UV-vis spectrophotometer, and Tecnai G2 F20 transmission electron microscope.

4：Experimental Procedures and Operational Workflow:

BSA-Cu NCs are synthesized by mixing CuSO4 with BSA, adjusting pH to 12 with NaOH, adding H2O2, and heating at 55°C for 1 hour. For detection, gossypol solutions are added to BSA-Cu NCs, mixed with Tris-HCl buffer, incubated at 37°C for 10 minutes, and fluorescence is measured.

5：Data Analysis Methods:

Fluorescence intensity is measured and analyzed for linear relationships with gossypol concentration. Selectivity is tested with interfering substances, and results are compared with HPLC.