Plasmonic nanoparticles with intra-nanogap produced by dealloying, method for preparing the same and use thereof

A method for preparing core-gap-shell nanoparticles having a hollow space between a core and a shell, in which a Raman-active material is disposed, comprising:

• a first step of preparing first metal core particles, a surface of which is modified with the Raman-active material;
• a second step of adding solutions, which comprise a second metal precursor, a base, and a third metal precursor, respectively, and a solution of a reducing agent to the surface-modified first metal core particles to form an alloy shell of the second metal and the third metal to form nanoparticles of the first metal core, the surface of which is modified with the Raman-active material, and an alloy shell comprising the second metal and third metal;
• and
• a third step of dealloying by selectively removing the second metal from the alloy shell by treating the nanoparticles formed in the second step with a second metal etchant;
• wherein the first metal has a higher reduction potential compared to the second metal.