1：Experimental Design and Method Selection:

The study used AFM-based Single Molecule Force Spectroscopy (SMFS) to analyze the adsorption of poly(acrylic acid) (PAA) on ZnO films. The methodology involved varying ZnO film morphology through electrodeposition and correlating surface chemistry with desorption studies.

2：Sample Selection and Data Sources:

Mirror polished stainless steel substrates (type 1.4301, X5CrNi18-10) were used. ZnO films were electrodeposited on these substrates. PAA was used as a model polyelectrolyte.

3：4301, X5CrNi18-10) were used. ZnO films were electrodeposited on these substrates. PAA was used as a model polyelectrolyte. List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: Equipment included a Reference 600 potentiostat (Gamry Instruments) for electrodeposition, a JPK Nano-Wizard III AFM (JPK Instruments) for SMFS, a NEON 40 FE-SEM (Carl Zeiss SMT AG) for SEM imaging, a Bruker Vertex 70 for PM-IRRAS, and an ESCA+ setup (Omicron NanoTechnology) for XPS. Materials included hexamethylenetetramine (HMTA), Zn(NO3)2·6H2O, NaClO4, NaOH, gold-coated Si-cantilevers (HQ:CSC17/Cr-Au, MikroMash), HS-PEG-NH2, S-NHS, EDC hydrochloride, HEPES buffer, PAA (MW 450,000, Sigma-Aldrich), and various solvents.

4：Experimental Procedures and Operational Workflow:

Stainless steel samples were cleaned and preconditioned. ZnO films were electrodeposited using a 3-electrode setup with constant current density. AFM tips were functionalized with PAA via thiol-gold chemistry. SMFS measurements were performed in an aqueous electrolyte (2 mM NaClO4, pH 7) at 298 K, with specific approach and retract speeds, setpoints, and dwell times. Data were collected and analyzed using JPK software.

5：Data Analysis Methods:

Force-distance curves were analyzed for rupture and plateau forces. Statistical evaluations, Gaussian fittings, and WLC model fittings were applied. XPS and PM-IRRAS were used for chemical analysis.