Due to characteristic physical properties such as surface plasmon resonance (SPR) and the availability of synthetic methods of gold and silver nanoparticles with various sizes and shapes, gold and silver nanoparticles (AuNPs and AgNPs) have found wide applications in the development of various DNA and protein detection methods. The extinction coefficient of AgNPs is ~4 times larger than that of AuNPs of the same size. Therefore, AgNPs are already widely used tools for signal amplification with commercialized staining solution in scanometric detection, SERS-based assays. However, in the case of AgNPs, there is no straightforward surface modification method for biosensing applications because AgNPs have tendency to chemically degrade under DNA hybridization and protein detection conditions. This limits the applications of AgNPs in biosensing applications. Core-shell Ag/Au approach is one solution to this problem by generating core-shell particles consisting of a core of Ag and a monolayer shell of Au that can be readily functionalized with biorecognition molecules such as DNA and antibodies. Herein, we report kinetically controlled, straightforward silver coating method for generating Au/Ag core-shell nanoparticles. Au/Ag core-shell nanoparticles in this case are consisted of DNA-modified Au core and a monolayer Ag shell that has stronger and different optical signals such as Raman signals from those of AuNPs. Further, we checked the stability of these new materials in various conditions, showed these DNA-em-Au/AgNPs recognize complementary target DNA to form aggregated DNA-em-Au/AgNPs and to induce color change, distinctly different from AuNP-aggregation-based color change. By tailoring DNA sequence and silver staining solution, one can easily generate very stable Au/Ag core-shell nanoparticles with stability, diversity(DNA, protein), and high sensitivity for various biosensing and programmed nanostructure assembly applications.