Monodisperse carboxy silica microspheres are widely used in biomedical research and diagnostics due to their uniform size and functional carboxyl groups. They serve as excellent carriers for drug delivery systems, allowing for controlled release of therapeutic agents. In diagnostics, these microspheres are employed in immunoassays and flow cytometry, where their consistent size ensures accurate and reproducible results. They are also utilized in chromatography as stationary phases, enhancing separation efficiency. Additionally, their carboxyl groups enable easy surface modification, making them suitable for attaching biomolecules like antibodies or DNA probes, which is crucial in targeted therapies and biosensing applications.