Used in biomedical applications such as targeted drug delivery, where the silica coating allows for easy functionalization with drugs or biomolecules while preventing aggregation and enhancing biocompatibility. Commonly employed in magnetic separation techniques for DNA, proteins, or cell isolation due to the stability and surface modifiability of the SiO2 layer. Applied in diagnostic imaging as contrast agents in MRI, benefiting from the protective silica shell that improves dispersion and reduces toxicity. Also utilized in catalysis, where the magnetic core enables easy recovery and reuse of catalysts after reaction, and in environmental remediation for the removal of pollutants from water through magnetic separation after adsorption.