Title :
Magnetoresistive Detection of Magnetic Beads and Nanoparticles: Spatial Resolution and Number Sensitve Detection
Author :
Weddemann, A. ; Auge, A. ; Albon, C. ; Wittbracht, F. ; Hutten, A.
Author_Institution :
Dept. of Phys., Thin Films & Nanostruct., Bielefeld Univ., Bielefeld, Germany
Abstract :
The detection capability of magnetic beads and nanoparticles by tunneling magnetoresistance sensors is analyzed in a finite element framework. The limitations for single particle detection and the determination of the particle position are investigated. It will be shown how varying the geometrical sensor design may readily be employed to adjust the setup to a specific measurement task. Especially, we show up strategies increasing the sensitivity by introducing magnetically soft areas. Further, number sensitive detections are discussed and the influence of dipolar particle coupling on the measured signal is calculated.
Keywords :
finite element analysis; magnetic particles; magnetic sensors; nanoparticles; tunnelling magnetoresistance; dipolar particle coupling; finite element framework; geometrical sensor design; magnetic beads; magnetic nanoparticles; magnetically soft areas; magnetoresistive detection; number sensitve detection; particle detection; particle position; tunneling magnetoresistance sensors; Magnetic analysis; Magnetic fields; Magnetic materials; Magnetic sensors; Magnetic separation; Magnetization; Magnetoresistance; Nanoparticles; Spatial resolution; Tunneling; magnetic beads; magnetic nanoparticles; magnetoresistive detection;
Conference_Titel :
Quantum, Nano and Micro Technologies, 2010. ICQNM '10. Fourth International Conference on
Conference_Location :
St. Maarten
Print_ISBN :
978-1-4244-5807-3
DOI :
10.1109/ICQNM.2010.13
