Synthesis of surface enhanced Raman scattering active magnetic nanoparticles for cell labeling and sorting

Here we report the synthesis of the magnetic nanocomposite nanoparticles with Fe 3 O 4 core and silver shell for cell imaging and separation. When the magnetic nanoparticles are decorated with surface enhanced Raman scattering (SERS) active molecules, they can be used for cell separation with unique optical signature. In this experiment, commercially available superparamagnetic nanoparticles (fluidMAG) with 50 nm diameter were used as the core. The shell layer was produced by the reduction of the silver salts. As a result of the reduction, nanocomposite magnetic nanoparticles with 60 nm diameter were obtained. To create unique SERS patterns for multiplexing, the surfaces of the nanoparticles were further modified with chloro-, bromo-, or fluorobenzenethiol. When these nanoparticles were incubated with 3T3 cells, it was found that the nanoparticles were located around the nucleus in the cytoplasm.