A straightforward and effective Al³⁺-directed electrostatic self-assembly strategy for linking Au nanoparticles (NPs) into one-dimensional (1D) or 2D nanoarrays has been demonstrated. In the self-assembly, Al³⁺ concentration played an important role in the Au NPs self-assembly, varying which size, shape, and surface plasmon resonance (SPR) properties of the Au nanoassemblies (NAs) could be well tuned.