1：Experimental Design and Method Selection:

The study focused on the self-assembly of GQDs in the presence of various metal ions. The methodology included synthesis of GQDs, their assembly into complex structures, and characterization using various spectroscopic and microscopic techniques.

2：Sample Selection and Data Sources:

GQDs were synthesized via an 'oxidation-cutting' method. The assembly of GQDs was investigated in the presence of various metal ions.

3：List of Experimental Equipment and Materials:

Instruments used included TEM (JEOL 3011 HREM, JEOL 2100F), AFM (Veeco, Dimension Icon AFM), SEM (FEI, Nova 200 Nanolab SEM/FIB), XPS (Kratos, Axis Ultra XPS), EDAX (EDAX XEDS system), Rigaku Ultima IV XRD, synchrotron based SAXS, fluorescence spectroscopy (Horiba, Fluoromax-3), UV/Vis spectroscopy (Agilent, 89090A), CD spectroscopy (JASCO, J-815), Raman spectroscopy (Renishaw InVia Reflex Micro Raman Spectrometer), FT-IR (Nicolet 6700 FTIR spectrometer), and confocal fluorescence microscopy (Leica, SP8 MP).

4：Experimental Procedures and Operational Workflow:

GQDs were synthesized and then assembled into various structures by adding metal ions. The assemblies were characterized using the aforementioned techniques to understand their morphology, structure, and formation mechanisms.

5：Data Analysis Methods:

The data were analyzed to understand the assembly patterns, the role of metal ions, and the symmetry of the assemblies. Computational studies including DFT and MD simulations were also performed to elucidate the assembly mechanisms.