In this work,a popcorn-like Au@Ag core-shell superstructure was synthesized using dopamine dithiocarbamate (DDTC)as reducing agent to control the discontinuous overgrowth of the Ag nanoparticles onto Au nanocubes (Au NCs).The popcorn-like nanoparticles exhibited tunable plasmon resonances over a spectral range in visible regions.And the thickness of hierarchical Ag shell was finely tuned in a range from 17 to 29 nm by simply varying the concentration of AgNO3solution.Furthermore,these nanoparticles could assemble into monolayer films using liquid-liquid interface self-assembly technique,and the surface enhanced Raman spectroscopy (SERS)performances of the prepared monolayer films with different AgNO3concentration were evaluated using crystal violet (CV)as the probe molecule.Meanwhile,three different excitation laser wavelengths (532 nm,633 nm,785 nm)were employed to investigate the effect of different laser wavelengths on the SERS performance of different substrates.This work indicates that the popcorn-like Au@Ag core-shell superstructures possess tunable localized surface plasmon resonance (LSPR)and SERS properties,which enables them to have great application prospect in solar cells,catalysis,chemical sensing and other fields.