Heterodimeric core-shell nanoparticle in which raman-active molecules are located at a binding portion of a nanoparticle heterodimer, use thereof, and method for preparing same

A dimer comprising two Au/Ag core-shell composites and a target oligonucleotide (T),

• wherein each of the two Au/Ag core-shell composites comprises an Au nanoparticle as a core;
• an Ag layer as a shell surrounding the Au nanoparticle;
• and an oligonucleotide of which one end is bonded to the Au nanoparticle via a functional group or a spacer molecule having the functional group, and the oligonucleotide is partially exposed to the outside of the shell;
• wherein one of the two Au/Ag core-shell composites has an oligonucleotide (A) capable of complementary base pairing with the oligonucleotide (T), and the other of the two Au/Ag core-shell composites has an oligonucleotide (B) capable of complementary base pairing with the oligonucleotide (T), and the two Au/Ag core-shell composites form the dimer via complementary base pairing through hydrogen bond between the partially exposed oligonucleotide (A) and the oligonucleotide (T) and complementary base pairing through hydrogen bond between the partially exposed oligonucleotide (B) and the oligonucleotide (T);
• wherein a distance between the two Ag layers of the dimer is 0.5 nm to 10 nm and thus the dimer has nano-junction exhibiting surface enhanced Raman Scattering effect between the two Ag layers of the dimer.