Title :
Scanning Magnetoresistance Microscopy for Imaging Magnetically Labeled DNA Microarrays
Author :
Chan, Mei-Lin ; Jaramillo, Gerardo ; Son, Ahjeong ; Hristova, Krassimira R. ; Horsley, David A.
Author_Institution :
Dept. of Mech. & Aeronaut. Eng., Univ. of California Davis, Davis, CA, USA
Abstract :
We demonstrate the use of a magnetic tunnel junction (MTJ) sensor as a probe for non-contact scanning microscopy of magnetically labeled DNA microarrays. Induced magnetic stray fields from 2.8 mum diameter magnetic particles are detected using the MTJ sensor, while two dimensional scanning generates the magnetic map of the DNA microarray with a spatial resolution of 1 mum over a large scan area exceeding 1 cm2. Current particle-sensor spacing of ~20 mum results in a detection resolution of ~30 magnetic particles within each 100 mum diameter DNA spot. Our results highlight the use of scanning magnetoresistive microscopy as a convenient and powerful technique for the accurate detection and identification of biomolecules tagged with magnetic particles.
Keywords :
biological techniques; biomagnetism; image resolution; lab-on-a-chip; magnetic particles; magnetic sensors; magnetic tunnelling; magnetoresistance; biomolecule identification; magnetic map; magnetic particle; magnetic stray field; magnetic tunnel junction sensor; magnetically labeled DNA microarrays; noncontact scanning microscopy; scanning magnetoresistance microscopy; size 100 mum; size 2.8 mum; two dimensional scanning; DNA microarray; biosensor; magnetic imaging; magnetic tunnel junction (MTJ);
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2009.2024876
