1：Experimental Design and Method Selection:

The study employs a simple and green method for in situ growth of gold nanoparticles on WS2 nanosheets to create Au-WS2 nanocomposites, which enhance ECL. The ECL interface is designed for label-free and non-destructive detection of DA.

2：Sample Selection and Data Sources:

WS2 nanosheets are exfoliated from bulk WS2 powder using BSA and ethanol. PC12 cells are cultured and used as a source of DA release, stimulated by K+ and inhibited by nifidipine.

3：List of Experimental Equipment and Materials:

Equipment includes TEM (Hitachi H-7650), HRTEM (JEOL-2100 F), UV-vis spectrophotometer (Cary 60), ECL analyzer (MPI-A), and a three-electrode setup with gold working electrode, platinum auxiliary electrode, and Ag/AgCl reference electrode. Materials include WS2 powder, HAuCl4, BSA, ethanol, K2S2O8, DA, and other chemicals from specified suppliers.

4：Experimental Procedures and Operational Workflow:

WS2 nanosheets are prepared by sonication and centrifugation. Au-WS2 nanocomposites are synthesized by adding HAuCl4 to WS2 nanosheets. The ECL interface is fabricated by dropping Au-WS2 onto a gold electrode. ECL measurements are performed in PBS buffer with K2S2O8, using cyclic voltammetry from -2.0 to 0 V at 0.1 V/s. DA detection involves adding DA solutions of varying concentrations and measuring ECL intensity.

5：0 to 0 V at 1 V/s. DA detection involves adding DA solutions of varying concentrations and measuring ECL intensity. Data Analysis Methods:

5. Data Analysis Methods: ECL intensity is analyzed to establish a linear relationship with DA concentration. Selectivity is tested against interferents like UA, AA, L-cys, and Glu. Stability and reusability are assessed through multiple detection cycles.