1：Experimental Design and Method Selection:

The study employed de-agglomeration of nanodiamonds via bead milling and ultrasound homogenization, followed by coating techniques including dip coating, electrophoretic deposition (EPD), and covalent immobilization using EDC/NHS-mediated coupling and DNA-mediated strategies. Theoretical models included electrostatic interactions, van der Waals forces, and covalent bonding mechanisms.

2：Sample Selection and Data Sources:

Substrates used were commercially pure grade 4 titanium and silicon wafers. Nanodiamonds were purchased from PlasmaChem GmbH. Data sources included SEM, AFM, TEM, fluorescence microscopy, nanoindentation, dynamic light scattering, and zeta potential measurements.

3：List of Experimental Equipment and Materials:

Equipment included planetary micro mill Pulverisette 7, ultrasound homogenizer HD 2200 Sonopuls, Delsa Nano Submicron Zetasizer, KSV Nima Dip Coater, IviumStat impedance analyzer, Diener electronic Plasmacleaner Femto, XL30 ESEM, JEOL JEM 1400 plus TEM, Nanowizard II AFM, Zeiss Axiovert 200M fluorescence microscope, Hysitron TI950 nano-indenter, Alpha-P total reflectance spectroscope. Materials included Yttrium-stabilised ZrO2 beads, APTES, EDC, NHS, MES buffer, PBS buffer, fluorescently labelled ssDNA.

4：Experimental Procedures and Operational Workflow:

De-agglomeration involved bead milling and ultrasound treatment. Coating procedures included dip coating (immersion and withdrawal at specified speeds), EPD (3V for 10 min), and covalent immobilization via silanization and EDC/NHS coupling. Functionalization included carboxylation of NDs and conjugation with ssDNA via thioester formation. Imaging and analysis involved SEM, AFM, TEM, fluorescence microscopy, and nanoindentation with specific parameters (e.g., 2000 μN force, 1.5 μm/s velocity).

5：5 μm/s velocity). Data Analysis Methods:

5. Data Analysis Methods: Data analysis included measurement of particle size distribution and zeta potential using dynamic light scattering, surface roughness parameters from AFM, lateral force analysis from nanoindentation, and fluorescence intensity quantification.