Practical Hall sensors for biomedical instrumentation

Development of instrumentation for medical diagnosis and bioscreening based on biological magnetic labeling and detection of superparamagnetic particles is an active, multidisciplinary field of research. The scalability, high sensitivity, and compatibility with semiconductor integrated circuits (ICs) makes thin film micro-Hall sensors a practical choice of technology for the detection of magnetic particles. We describe the results of our systematic study on the fabrication of high-sensitivity micro-Hall devices using InSb, InAs, GaN, and bismuth thin films for detection of superparamagnetic particles coated with biological molecules. Sensor fabrication, scalability, magnetic-field sensitivity, and biological functionalization are discussed.