1：Experimental Design and Method Selection:

The study involved constructing a FRET system via physical blending of SRhB and LS, utilizing electrostatic interactions for self-assembly. Methods included UV-vis spectroscopy, DLS, Zeta potential, SEM, TEM, 1H-NMR, QCM-D, and fluorescence techniques.

2：Sample Selection and Data Sources:

LS was obtained from sulfite pulping processes and purified. SRhB was synthesized as per literature. Buffer solutions of various pH values were prepared using citric acid and phosphate buffers.

3：List of Experimental Equipment and Materials:

Equipment included Waters 1515 Isocratic HPLC pump/Waters 2487 GPC, Elementar Vario EL cube, UV-2450 spectrometer, Malvern Zetasizer 2000, HITACHI H-7650 TEM, Advance Digital 400 MHz NMR spectrometer, HITACHI F-4600 luminoscope, and Quantaurus-Tau C11367-11. Materials included LS, SRhB, sodium dihydrogen phosphate, sodium hydrogen phosphate, citric acid, trisodium citrate, PSSNa, PDAC, and various buffers.

4：Materials included LS, SRhB, sodium dihydrogen phosphate, sodium hydrogen phosphate, citric acid, trisodium citrate, PSSNa, PDAC, and various buffers. Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: SRhB NPs were prepared by solvent exchange, then blended with LS solution. The composite was characterized, and pH-response studies were conducted by adding SRhB/LS to buffer solutions and measuring fluorescence. Adsorption studies used QCM-D and Zeta potential measurements.

5：Data Analysis Methods:

Data were analyzed using statistical methods and software associated with the instruments, including fitting equations for pH-response curves and lifetime decay analysis.