Nanoassembly methods for producing quasi-3D plasmonic films with periodic nanoarrays of nano-sized surface features. A sacrificial layer is deposited on a surface of a donor substrate having periodic nanoarrays of nanopattern features formed thereon. A plasmon film is deposited onto the sacrificial layer and a dielectric spacer is deposited on the plasmon film. The donor substrate having the sacrificial layer, plasmon film, and dielectric spacer thereon is immersed in a bath of etchant to selectively remove the sacrificial layer such that the plasmon film and the dielectric spacer thereon adhere to the surface of the donor substrate. The dielectric spacer and the plasmon film are mechanically separated from the donor substrate to define a quasi-three dimensional (3D) plasmonic film having periodic nanoarrays of nano-sized surface features defined by the nanopattern features of the donor substrate surface. The quasi-3D plasmonic film is then applied to a receiver substrate.