LAUSR

Abstract Magnetic polyphosphazene (MPZS) particles coated by Ag nanoparticles (MPZS-Ag) have been developed as surface enhanced Raman spectroscopy (SERS) substrates for sensitive detection of melamine in aqueous solutions and milk samples. 5,5′-Dithiobis-(2-nitrobenzoic acid) (DTNB) was used as model analyte to test the SERS activity of the MPZS-Ag particles. The prepared MPZS-Ag particles possess both magnetic responsiveness and excellent SERS properties. SERS detection of different concentrations of melamine aqueous solutions and spiked milk samples were performed by the MPZS-Ag particles. The limit of detection (LOD) of the melamine in aqueous solutions was 10−7 mol/L (0.0126 mg/L) and 0.6 mg/L in real milk samples using the MPZS-Ag particles as SERS substrates. The LOD of the melamine are much lower than the safety values of Food and Drug Administration and Codex Alimentarius Commission. These results indicate that the MPZS-Ag particles have promising application prospect for SERS analysis in food safety fields.