| Abstract: | In this study, surface‐enhanced Raman spectroscopy (SERS)‐encoded magnetic nanoparticles (NPs) are prepared and utilized as a multifunctional tagging material for cancer‐cell targeting and separation. First, silver‐embedded magnetic NPs are prepared, composed of an 18‐nm magnetic core and a 16‐nm‐thick silica shell with silver NPs formed on the surface. After simple aromatic compounds are adsorbed on the silver‐embedded magnetic NPs, they are coated with silica to provide them with chemical and physical stability. The resulting silica‐encapsulated magnetic NPs (M‐SERS dots) produce strong SERS signals and have magnetic properties. In a model application as a tagging material, the M‐SERS dots are successfully utilized for targeting breast‐cancer cells (SKBR3) and floating leukemia cells (SP2/O). The targeted cancer cells can be easily separated from the untargeted cells using an external magnetic field. The separated targeted cancer cells exhibit a Raman signal originating from the M‐SERS dots. This system proves to be an efficient tool for separating targeted cells. Additionally, the magnetic‐field‐induced hot spots, which can provide a 1000‐times‐stronger SERS intensity due to aggregation of the NPs, are studied. |
