Magnetic Biosensor for Medical Diagnosis

One of the major challenges in medicine is the rapid and accurate measurement of protein biomarkers, cells, and pathogens in biological samples. Biosensors based on magnetic detection emerge as a promising diagnostic platform. Due to the intrinsically negligible magnetic susceptibilities of biological entities, magnetic detection experiences little interference from native biological samples; even optically turbid samples will often appear transparent to magnetic fields. Biomolecules or cells of interests, when magnetically labeled, however, can attain a high contrast against complex biological background. This presentation will review such magnetic sensing technologies, specifically focusing on a general detection platform termed diagnostic magnetic resonance (DMR). Similar to clinical MRI, the DMR utilizes magnetic nanoparticles to modulate the spin-spin relaxation time of neighboring water molecules. Numerous assay configurations and nanoparticles have been designed to detect a wide range of targets including DNA, mRNA, proteins, enzymatic activity, metabolites, drugs, pathogens, and tumor cells. The capabilities of DMR technology have been considerably advanced with the development of a miniaturized, chip-based NMR detector system that is capable of performing highly sensitive measurements on microliter sample volumes and in a multiplexed format. With these and on-going advances in system design, the DMR technology holds great promise as a high-throughput, low-cost, and portable platform in clinical and point-of-care settings.

Dr. Lee is Associate Professor in Radiology at Harvard Medical School, Director of the Biomedical Engineering Program at the Center for Systems Biology, Massachusetts General Hospital (MGH), and Hostetter MGH Research Scholar. He received his Ph.D. in Physics from Harvard University and completed his postdoctoral training at MGH. Dr. Lee has extensive experience in nanomaterials, biophysics, microfluidics, and electrical engineering. His research focuses on developing novel biomedical sensors for clinical applications, for example, the world’s smallest portable NMR device, integrated circuit (IC) chips for cancer cell detection, and a point-of-use device for pathogen detection. Many of these systems have been translated clinical applications.