Development of Magnetic Particle-Based Immunoassays and Their Applications in Diabetes Monitoring

In addition to blood glucose testing, monitoring of blood glycated proteins got considerable attention on the glycemic control of diabetes. Glycated albumin has been reported as a good complementary to or better indicator than glycated hemoglobin for the evaluation of short-term glycemic control. Herein, the development of magnetic particle-based immunoassays for blood glycated proteins is demonstrated. Spherical magnetic particles are fabricated composed of a polystyrene core covered with a thin layer of Fe3O4 and SiO2. The core-shell structure allow us to control a wide size range by using the polystyrene cores of different size, and the silica outer layer can be functionalized easily with silane coupling agents. Aminophenylboronic acid is covalently immobilized onto magnetic particles for the affinity isolation of glycated proteins, while horseradish peroxidase labeled antibodies are used for detection. The assays are optimized and applied successfully to the determination of glycated albumin in standard and human serum samples and show good potential as tools for diabetes monitoring.