In situ detection of single micron-sized magnetic beads using magnetic tunnel junction sensors
- 16 June 2005
- journal article
- Published by AIP Publishing in Applied Physics Letters
- Vol. 86 (25) , 253901
- https://doi.org/10.1063/1.1952582
Abstract
We have demonstrated the use of highly sensitive magnetic tunnel junction(MTJ)sensors for the detection of individual micron-sized magnetic labels. By integrating the MTJsensor into a microfluidic channel, we were able to detect the presence of moving superparamagnetic beads (Dynabeads® M-280) in real time by direct measurement of the magnetic dipole fields associated with single beads. The dipolar fields of a single bead were sufficient to obtain a signal of 80 μ V with signal to noise ratio of 24 dB in an applied field of 15 Oe . Our data show conclusively that MTJsensors are very promising candidates for future applications involving the accurate detection and identification of biomolecules with magnetic labels.Keywords
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