Used in biomedical applications such as targeted drug delivery, magnetic separation of cells or biomolecules, and MRI contrast enhancement. The SiO2 coating improves biocompatibility and prevents aggregation, while the epoxy surface groups enable covalent functionalization with antibodies, proteins, or drugs. Also applied in environmental remediation for removal of heavy metals or pollutants from water via magnetic separation and adsorption. Commonly used in diagnostic kits and biosensors due to their stability and ease of manipulation with external magnetic fields.