1：Experimental Design and Method Selection:

The study integrates aggregation-induced emission (AIE) properties of Cu nanoclusters (NCs) with Ca2+-triggered gelation of alginate to create pH-responsive materials. Methods include synthesis of Cu NCs using glutathione as a reducing agent and ligand, fabrication of the responsive system by dispersing sodium alginate, CaCO3 nanoparticles, and Cu NCs in aqueous solution, and testing for glucose sensing using glucose oxidase to produce H+.

2：Sample Selection and Data Sources:

Cu NCs are synthesized from copper nitrate and glutathione. Materials such as sodium alginate, CaCO3 nanoparticles (80 nm diameter), glucose, glucose oxidase, and various interferents (e.g., ascorbic acid, cysteine) are purchased from commercial suppliers. Human serum samples are used for recovery tests.

3：List of Experimental Equipment and Materials:

Instruments include a Philips CM20 transmission electron microscope (TEM) for morphology, Spectrofluorometer FS5 for fluorescence spectra, environmental scanning electron microscope (ESEM, FEI/Philips XL30) for SEM images, ESCALAB-MKII 250 X-ray photoelectron spectrometer (XPS) for surface composition, and unspecified spectrometers for PL measurements. Materials include glutathione, copper nitrate, sodium alginate, CaCO3 nanoparticles, glucose, glucose oxidase, ascorbic acid, cysteine, dopamine, fructose, lactose, PBS buffer, and others from suppliers like Aladdin, Kermel, Sigma-Aldrich, Ruicheng NanoMaterials Technology Co., Ltd., biosharp, and Beijing Innochem technology co., LTD.

4：Experimental Procedures and Operational Workflow:

Cu NCs are synthesized by mixing Cu(NO3)2 and GSH solutions, adjusting pH to 7.0. The pH-responsive material is fabricated by dispersing sodium alginate, CaCO3 nanoparticles, and Cu NCs in water, then adding HCl to trigger gelation and PL enhancement. For glucose sensing, samples are prepared with varying glucose concentrations, incubated, and PL spectra recorded. Selectivity tests involve adding interferents, and recovery tests use human serum samples.

5：The pH-responsive material is fabricated by dispersing sodium alginate, CaCO3 nanoparticles, and Cu NCs in water, then adding HCl to trigger gelation and PL enhancement. For glucose sensing, samples are prepared with varying glucose concentrations, incubated, and PL spectra recorded. Selectivity tests involve adding interferents, and recovery tests use human serum samples. Data Analysis Methods:

5. Data Analysis Methods: PL intensity is measured and correlated with glucose concentration for linear regression analysis. Limit of detection is calculated, and statistical measures like relative standard deviation (RSD) and recovery percentages are computed. Data from TEM, SEM, XPS, and fluorescence spectra are analyzed to characterize materials and mechanisms.