Detection of a countable number of magnetic particles for biological applications using a Hall device

Abstract

We fabricated a magnetic field sensor made of an InAs quantum-well. Various numbers of magnetic particles were located on the sensor and the stray field generated by the magnetic particles was detected using micro-Hall magnetometry at room temperature. A numerical calculation carried out for this device successfully explained the experimental results and a useful equation relating the signal of the device and the number of particles was deduced.