Au@AgNCs self assembled in the bilayer LB film of SA.

The as prepared films have been established as a promising SERS active substrate.

AEFs ∼10¹³ orders of magnitude have been estimated from the SER(R) S spectrum of R6G.

Correlations between the optical properties and surface morphologies have been done.

E-field distributions have been estimated with the aid of 3D-FDTD simulations.