Gold or silver nanoparticles decorating superparamagnetic calcium ferrite nanoparticles for application in SERS

摘要

In this work, we report the synthesis of Ag and Au nanoparticles capped with either cysteamine or cysteine. Purification of these NPs turned out to originate irreversible aggregation, so that the coupling of NH2 groups from Au (or Ag) nanoparticles to OH groups of magnetic calcium ferrite (CaFe2O4) nanoparticles (MNPs) would not work as expected. Therefore, naked metallic Ag or Au nanoparticles were produced and connection to calcium ferrite was performed by first attaching cysteine to the MNPs and then using the resulting SH pending groups to interact with the metallic surface.