Gold nanoparticle self-assembly behaviour on a mica surface was investigated. A large-scale modified partially hydrated polyacrylamide network on a mica surface was successfully fabricated with a simple method. Gold nanoparticles were self-assembled onto a two-dimensional polymer network template by electrostatic interaction, and an interesting nanostructured gold morphology with controllable interparticle spacing was formed on the mica surface. By adjusting the gold aqueous concentrations, the particle distance could be optimized to approach strongest coupling between adjacent particles and match the plasmon resonance wavelength to the laser excitation wavelength. Thus, the spacing between nanoparticles could be controlled for tunable surface-enhanced Raman scattering substrates for optimal signal amplification.