Used in biomedical applications such as targeted drug delivery, where the silica coating allows for surface functionalization with drugs or biomolecules while protecting the magnetic core. Enables magnetic separation in diagnostic assays, including DNA, protein, and cell isolation, due to easy manipulation under external magnetic fields. Applied in imaging techniques like MRI as contrast agents, benefiting from the biocompatible SiO2 layer that reduces toxicity and prevents aggregation. Also utilized in environmental remediation for removal of pollutants from water through magnetic retrieval after adsorption. Common in biosensors and lab-on-a-chip devices where controlled movement and high surface area improve detection sensitivity.