Fig. 4From: Core-shell of FePt@SiO2-Au magnetic nanoparticles for rapid SERS detection a TEM images of Au-FePt@SiO2-N (0.3 M of EDS and 142.8 μM of Au nanoparticles), b Zeta potential of FePt@SiO2-N with various gold nanoparticles concentrations, and c XPS analysis (Au-4f) of pristine gold nanoparticles and Au-FePt@SiO2-NBack to article page