Tuning the interparticle distances in self-assembled gold nanoparticle films with their plasmonic responses

•Investigates the localized surface plasmon resonance (LSPR) properties of 2D film of Au nanoparticles on a glass substrate formed at the water-hexane interface.•2D films of the Au nanoparticles with the ability to control the interparticle distances by the alkyl chain lengths of alkanethiol.•Density functional theory (DFT) calculation and finite-difference time domain (FDTD) simulation have been used to confirm the interparticle distances.•Au nanoparticles and also exhibit distinct interparticle-distance-dependent surface-enhanced Raman scattering (SERS) characteristics.