Detection of DNA labeled with magnetic nanoparticles using MgO-based magnetic tunnel junction sensors

Abstract
We have demonstrated the detection of 2.5 μ M target DNA labeled with 16 nm Fe 3 O 4 nanoparticles (NPs) and 50 nm commercial MACS™ NPs using arrays of magnetic tunnel junctionsensors with (001)-oriented MgO barrier layers. Signal-to-noise ratios of 25 and 12 were obtained with Fe 3 O 4 and MACS™ NPs, respectively. These data show conclusively that MgO-based MTJsensor arrays are very promising candidates for future applications involving the accurate detection and identification of biomolecules tagged with magnetic nanoparticles.