TY - JOUR
T1 - The scanning TMR microscope for biosensor applications
AU - Vyas, Kunal N.
AU - Love, David M.
AU - Ionescu, Adrian
AU - Llandro, Justin
AU - Kollu, Pratap
AU - Mitrelias, Thanos
AU - Holmes, Stuart
AU - Barnes, Crispin H.W.
N1 - Publisher Copyright:
© 2015 by the authors.
PY - 2015
Y1 - 2015
N2 - We present a novel tunnel magnetoresistance (TMR) scanning microscope set-up capable of quantitatively imaging the magnetic stray field patterns of micron-sized elements in 3D. By incorporating an Anderson loop measurement circuit for impedance matching, we are able to detect magnetoresistance changes of as little as 0.006%/Oe. By 3D rastering a mounted TMR sensor over our magnetic barcodes, we are able to characterise the complex domain structures by displaying the real component, the amplitude and the phase of the sensor's impedance. The modular design, incorporating a TMR sensor with an optical microscope, renders this set-up a versatile platform for studying and imaging immobilised magnetic carriers and barcodes currently employed in biosensor platforms, magnetotactic bacteria and other complex magnetic domain structures of micron-sized entities. The quantitative nature of the instrument and its ability to produce vector maps of magnetic stray fields has the potential to provide significant advantages over other commonly used scanning magnetometry techniques.
AB - We present a novel tunnel magnetoresistance (TMR) scanning microscope set-up capable of quantitatively imaging the magnetic stray field patterns of micron-sized elements in 3D. By incorporating an Anderson loop measurement circuit for impedance matching, we are able to detect magnetoresistance changes of as little as 0.006%/Oe. By 3D rastering a mounted TMR sensor over our magnetic barcodes, we are able to characterise the complex domain structures by displaying the real component, the amplitude and the phase of the sensor's impedance. The modular design, incorporating a TMR sensor with an optical microscope, renders this set-up a versatile platform for studying and imaging immobilised magnetic carriers and barcodes currently employed in biosensor platforms, magnetotactic bacteria and other complex magnetic domain structures of micron-sized entities. The quantitative nature of the instrument and its ability to produce vector maps of magnetic stray fields has the potential to provide significant advantages over other commonly used scanning magnetometry techniques.
KW - 3D magnetic stray field mapping
KW - Domain wall characterisation
KW - Magnetic carriers
KW - TMR-scanning microscope
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U2 - 10.3390/bios5020172
DO - 10.3390/bios5020172
M3 - Article
C2 - 25849347
AN - SCOPUS:84935517782
VL - 5
SP - 172
EP - 186
JO - Biosensors
JF - Biosensors
SN - 2079-6374
IS - 2
ER -