Synthesis and evaluation of the SERS effect of Fe 3 O 4 -Ag Janus composite materials for separable, highly sensitive substrates.

Fe 3 O 4 -Ag Janus composites were synthesized using a two-step solvothermal method. The optimal growth process was determined by investigating the relationship between the particle morphologies and reaction time. Magnetic and Raman spectroscopic measurements showed that the as-synthesized Janus composites have both good magnetic response and significant surface-enhanced Raman scattering (SERS) effects, as well as reproducibility. The calculated Raman enhancement factor reached an unprecedented magnitude of 10 9 compared with the values of other Fe 3 O 4 -Ag compounds. Furthermore, the SERS effect was exhibited even at a concentration of probe molecules as low as 10 -13 M. This demonstrates that the as-synthesized Fe 3 O 4 -Ag Janus composite particles have promise for application as separable, highly sensitive SERS substrates.