1：Experimental Design and Method Selection

The study employed Raman scattering, X-ray Photoelectron Spectroscopy, UV-vis absorption, Transmission Electron Microscopy, and Density Functional Theory calculations to investigate the interaction between trans-zeatin and gold nanoparticles obtained by laser ablation.

2：Sample Selection and Data Sources

Three different gold colloids were prepared: Au_chem by chemical reduction, Au_PLAL by laser ablation in pure water, and Au_citr_PLAL by laser ablation in citrate solution. Trans-zeatin was dissolved in aqueous solution with NaOH and added to the Au colloidal suspensions.

3：List of Experimental Equipment and Materials

Equipment included a Q-switched Nd:YAG laser for laser ablation, a Cary 5 Varian spectrophotometer for UV-vis absorption, a RM2000 Renishaw micro-Raman apparatus for Raman spectra, a TEM Philips CM12 cryo-gatan UHRST 3500 for TEM imaging, and a Malvern Zetasizer Nanoseries apparatus for ζ-potential measurements. Materials included tetrachloroauric acid, sodium citrate, and trans-zeatin.

4：Experimental Procedures and Operational Workflow

Gold nanoparticles were prepared by chemical synthesis or laser ablation. Zeatin was added to the colloidal suspensions at different concentrations. The interaction between zeatin and gold nanoparticles was studied using various spectroscopic and microscopic techniques.

5：Data Analysis Methods

Data analysis was performed using Origin Pro 8 software. DFT calculations were conducted with Gaussian 09 software using the B3LYP exchange-correlation functional and two different basis sets.