Integration of dual core-shell structured magnetic mesoporous carbon microspheres and nitrogen-doped carbon dots for specific preconcentration and sensitive fluorescent determination of PFOS in egg samples

Magnetic mesoporous carbon microsphere with dual core-shell structure was constructed. • Fe 3 O 4 @PDA@CMS with uniform size and good magnetic separability enables efficient PFOS enrichment. • The material was applied in efficient purification of PFOS in real samples. • PFOS in egg extracts measured very accurately, well matching of the LC-MS/MS result. The accurate determination of perfluorooctane sulfonate (PFOS) in biological samples is challenging because of its trace concentrations and complex matrix interferences. In this work, a dual core-shell structured magnetic mesoporous carbon microsphere (Fe 3 O 4 @PDA@CMS) with Fe 3 O 4 nanoparticles as the carrier and magnetic core, polydopamine (PDA) adhesive layer, and glucose-derived carbon precursor was prepared for the enrichment of PFOS in biological samples. The Fe 3 O 4 @PDA@CMS displayed a uniform size distribution, good monodispersity, and rapid magnetic separation ability, effectively simplifying enrichment and pretreatment. Using Fe 3 O 4 @PDA@CMS for magnetic solid-phase extraction (MSPE) combined with nitrogen-doped carbon dots-based fluorescence analysis, an MSPE-fluorescence method was developed. This method exhibited a linear range of 1.0–120.0 ng/L and a LOD of 0.02 ng/L for PFOS detection. PFOS concentrations in egg extract samples were accurately measured by this method, and the results were consistent with those obtained by LC-MS/MS. This analytical strategy is accurate and simple, and holds promise for the rapid, sensitive determination of PFOS in other complex biological matrices. Download: Download high-res image (123KB) Download: Download full-size image