1：Experimental Design and Method Selection:

The study involved synthesizing layered rare-earth hydroxides (LRHs) using sulfosalicylic acid (SSA) as an intercalation agent via hydrothermal reaction, followed by mechanical exfoliation to obtain nanosheets. These nanosheets were characterized and used to fabricate a thin film sensor through electrophoretic deposition. The sensing properties were evaluated for chromate and bilirubin detection using fluorescence spectroscopy.

2：Sample Selection and Data Sources:

Solutions of Tb(NO3)3 and Y(NO3)3 were mixed, with pH adjusted using aqueous ammonia. SSA was neutralized and added. Nanosheets were prepared from LRHs by ultrasonic exfoliation in n-butanol. Sensing tests used solutions of K2Cr2O7 (converted to CrO4^2-) and bilirubin in serum.

3：List of Experimental Equipment and Materials:

Equipment included X-ray diffractometer (D8 Advance, Bruker AXS), scanning electron microscope (S-4800, Hitachi), transmission electron microscope (JEM2100, Hitachi), nanoparticle size and zeta potential analyzer (NANO ZS3600), fluorescence spectrometer, UV spectrophotometer (Agilent Cary UV-8000), and ellipsometer. Materials included Tb(NO3)3, Y(NO3)3, SSA, NaOH, aqueous ammonia, n-butanol, conductive glass (ITO), polystyrene, K2Cr2O7, and bilirubin.

4：Experimental Procedures and Operational Workflow:

LRHs were synthesized hydrothermally at 120°C for 24 hours, washed, and dried. Nanosheets were obtained by ultrasonic exfoliation for 40 minutes. The thin film was prepared by electrophoretic deposition on ITO glass and coated with polystyrene. Sensing involved placing analyte solutions on the film and measuring luminescence intensity changes.

5：Data Analysis Methods:

Data were analyzed using the Stern-Volmer equation for quenching kinetics, and mechanisms were studied through UV and fluorescence spectroscopy overlap.