Magnetic Fe 3 O 4 /Ag hybrid nanoparticles as surface-enhanced raman scattering substrate for trace analysis of furazolidone in fish feeds

Nanoparticles (NPs) composed of ferromagnetic and noble metal materials show dual functions of magnetic activity and local surface plasmon response and have great potential as substrates for surface-enhanced Raman scattering (SERS) in trace analysis. Easy-to-prepare superparamagnetic Fe3O4/Ag hybrid NPs were synthesized and optimized by adjusting the ratio of silver particles aggregated with APTMS-modified Fe3O4 NPs. The hybrid NPs were assembled under an external magnetic field before being used as substrate for SERS analysis. The SERS spectral features of furazolidone standard solution were clearly identified at concentrations as low as 40 ngmL-1, and furazolidone in fish feeds could be detected at 500 ng g-1. The results indicated that the Fe3O4/Ag hybrid NPs as SERS substrates had a great potential for detection of trace amount of furazolidone and other prohibited or restricted antibiotics in the animal and fish feeds.