Advances in magnetic nanomaterials for biomedical sample pretreatment: synthesis, functionalization, and applications in magnetic solid-phase extraction

Magnetic nanomaterials (MNMs) are highly effective sorbents for biomedical sample pretreatment, leveraging their superparamagnetism, large specific surface area, and tunable surface functionalities. This review comprehensively examines MNM classification, synthesis techniques, and functionalization approaches, highlighting their pivotal role in magnetic solid-phase extraction (MSPE) for analyte enrichment. We systematically detail MNM applications in biomedical sample processing, focusing on MSPE for efficient nucleotide isolation, specific protein capture, and ultrasensitive biomarker detection. While MNM-based MSPE offers significant advantages in sensitivity, selectivity, and operational simplicity, challenges remain in achieving reproducible synthesis and deepening the mechanistic understanding of adsorption processes. Future research should prioritize developing automated MSPE platforms and multifunctional MNMs capable of addressing complex clinical matrices. This work provides a valuable reference for designing next-generation analytical systems utilizing MNMs.