Facile synthesis of Au nanoparticle-coated FeO magnetic composite nanospheres and their application in SERS detection of malachite green.

A facile method for synthesizing Au nanoparticle-coated FeO magnetic composite nanospheres (FeO@Au MCS) via seed-mediated growth and iterative reduction is reported. The nanospheres were then successfully used to detect malachite green (MG) residues in water bodies via surface-enhanced Raman scattering (SERS) technique. FeO@Au MCS has excellent optical properties and superparamagnetism; it can be dispersed into the solution to fully adsorb target molecules and then collected with a magnet to increase the molecular density and the number of SERS hot spots.