Ag/ZnFe₂O₄-Au NPs-Based SERS Detection of Rosiglitazone in Seawater

Pharmaceutical and personal care products (PPCPs) have attracted considerable attention as emerging environmental contaminants. Among them, rosiglitazone (RSG), a widely used thiazolidinedione hypoglycemic agent in clinical therapy, has raised growing environmental and health concerns due to its continuous release into aquatic ecosystems. In this work, a novel magnetic semiconductor material Ag-doped ZnFe₂O₄, was firstly prepared by using hydrothermal method. Subsequently, Au nanoparticles (Au NPs) were anchored onto the surface of Ag/ZnFe₂O₄ to construct a highly sensitive SERS substrate (denoted as Ag/ZnFe₂O₄-Au NPs) for sensing the trace-level RSG. The enhancement mechanism analysis reveals that the synergistic contribution of chemical enhancement from the Ag/ZnFe₂O₄ semiconductor, electromagnetic enhancement from Au NPs, and magnetic-field-induced coupling endows the substrate with a remarkable enhancement factor of 7.74 × 10⁷. This proposed assay for RSG detection exhibits high sensitivity and reaches a limit of detection of 3 × 10^-8 mol/L, accompanying a wide linear dynamic detection range from 6.67 × 10^-5 to 6.67 × 10^-8 mol/L, with correlation coefficient (R²) of 0.9830. In addition, the high stability and the excellent selectivity against the coexisting objects offer potential for real samples measurement. The developed Ag-doped magnetic semiconductor-metal composite-based SERS strategy provides a potential for PPCPs monitoring in real environmental samples.