Fabrication of magnetic Au/Fe3O4/MIL-101(Cr) (AF-MIL) as sensitive surface-enhanced Raman spectroscopy (SERS) platform for trace detection of antibiotics residue

Fabrication of a magnetic substrate based on metal–organic frameworks (MOFs) with high sensitivity and stability for surface-enhanced Raman scattering (SERS) analysis were reported in this paper. MIL-101(Cr) nanoparticle prepared via a traditional hydrothermal reaction, which was combined with Fe3O4 to synthesize the Fe3O4/MIL-101(Cr) composites. Then, the concentration of chloroauric acid and the time of reduction reaction were adjusted to acquire the optimal Au/Fe3O4/MIL-101(Cr) (AF-MIL) SERS substrate. The detection ability of the substrate can down to 10-8 mol/L for Rhodamine 6G (R6G) as probe molecule, and the relative standard deviation (RSD) is only about 4.48 %, which indicates that it possesses wonderful SERS performance and uniformity. Finally, the as-synthesized substrate has been adopted to test the trace level sulfapyridine, with its desirable detection ability can down to 10-6 mol/L. Such desirable SERS substrate with facile and effective operation holds great promise in the fast sensitive detection of the antibiotic residue and some other pollutants in environment.