Room-temperature detection of a single commercial superparamagnetic bead (1.2 μm in diameter) suitable for biological applications has been realized using an InAs quantum-well micro-Hall sensor. The detection was demonstrated using phase-sensitive detection on a single Hall cross as well as in a Hall gradiometry setup. The high signal to noise ratio, obtained in both configurations, promises detection of single nanometer-size particles by further miniaturization of the device to submicron dimensions.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)