ABSTRACT
Beginning with magnetoresistance sensors such as the ordinary magnetoresistance (the Hall effect) and anisotropic magnetoresistance, the giant magnetoresistance effect is systematically explained through simple analogies, discussion of parameter optimization and presentation of some GMR sensor structures. Tunneling magnetoresistance is defined and the relative merits/demerits of GMR and TMR sensors are brought out. Magnetic nanoparticle probes for DNA analysis, protein and virus detection and analyzing telomerase activity are briefly surveyed. Protease-specific nanosensors for MRI, magnetic relaxation switch immunosensors, needle-type SV-GMR sensor for biomedical applications, superconductive magnetic nanosensor, electron tunneling-based magnetic field sensor, nanowire magnetic compass and position sensor are a few impressive examples of magnetic nanosensors developed. Design considerations, passivation, and magnetic nanotag issues in a magneto nanosensor microarray biochip and its utilization in DNA and tumor marker detection are looked into. Other devices examined are a GMR-based detection system with zeptomole sensitivity and a bead array counter biosensor.
