Magnetic ferroferric oxide/phenolic resin/silver core–shell nanocomposite as recyclable substrates for enhancing surface-enhanced Raman scattering

Abstract

With the development of nanotechnology, the preparation method of surface-enhanced Raman scattering (SERS) substrate has made significant progress, which promotes the application of SERS in food safety, environmental protection, and medical testing. We reported on the fabrication of silver-coated magnetic Fe3O4@phenolic resin (Fe3O4@RF) core–shell particles by a facile solvothermal method, followed by deposition of high-density Ag nanoparticles onto the phenolic resin surfaces through an in-situ reduction process. Analysis of Raman spectroscopy was performed by laser Raman spectrometer. The as-synthesized Ag-coated Fe3O4@RF particles as sensitive SERS substrates showed outstanding SERS performances toward probe molecules of 4-aminothiophenolas with a detection limit of 1 × 10–9 mol L–1. Moreover, the enhancement factor of the substrate was calculated to be about 2.86 × 105. Importantly, profiting from the excellent magnetism, the signal attenuated slightly only after three cycles measurements of SERS based on such composite substrates, indicating that Fe3O4@RF@Ag magnetic composite microspheres possessed the outstanding repeatability. On the basis of these results, it is believed that such Fe3O4@RF@Ag substrates are promising for the reusable detection of toxic molecules in practical applications.