Highly-Sensitive Magnetic Tunnel Junction Based Flow Cytometer

Flow cytometers are important instruments for biological and biomedical analyses. These instruments are large and expensive, and researchers are continuously striving to come up with smaller, cheaper, and more energy-efficient flow cytometers. In this work, we present a highly-sensitive magnetic tunnel junction (MTJ) based flow cytometer. An externally magnetized magnetic beads labeling cells were placed above an MTJ sensor that can measure the stray field surrounding the beads. It was found that each time labeled cells pass through the sensitive area of the sensor, a peak of signal was observed. The results demonstrate a novel MTJ based flow cytometer design approach for accurate detection of magnetically labeled cells.