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Silver-coated magnetite–carbon core–shell microspheres as substrate-enhanced SERS probes for detection of trace persistent organic pollutants

2012; Royal Society of Chemistry; Volume: 4; Issue: 16 Linguagem: Inglês

10.1039/c2nr31061a

2040-3372

Qiao An, Peng Zhang, Junmei Li, Wanfu Ma, Jia Guo, Jun Hu, Changchun Wang,

Biosensors and Analytical Detection

Highly active surface-enhanced Raman scattering (SERS) substrates of Ag nanoparticle (Ag-NP) modified Fe3O4@carbon core–shell microspheres were synthesized and characterized. The carbon coated Fe3O4 microspheres were prepared via a one-pot solvothermal method and were served as the magnetic supporting substrates. The Ag-NPs were deposited by in situ reduction of AgNO3 with butylamine and the thickness of the Ag-NP layer was variable by controlling the AgNO3 concentrations. The structure and integrity of the Fe3O4@C@Ag composite microspheres were confirmed by TEM, XRD, VSM and UV-visible spectroscopy. In particular, the Ag-NP coated Fe3O4@carbon core–shell microspheres were shown to be highly active for SERS detections of pentachlorophenol (PCP), diethylhexyl phthalate (DEHP) and trinitrotoluene (TNT). These analytes are representatives of environmentally persistent organic pollutants with typically low SERS activities. The results suggested that the interactions between the carbon on the microsphere substrates and the aromatic cores of the target molecules contributed to the facile pre-concentration of the analytes near the Ag-NP surfaces.