Sensitive magnetic biodetection using magnetic multi-core nanoparticles and RCA coils
Journal article, 2017

We use functionalized iron oxide magnetic multi-core particles of 100 nm in size (hydrodynamic particle diameter) and AC susceptometry (ACS) methods to measure the binding reactions between the magnetic nanoparticles (MNPs) and bio-analyte products produced from DNA segments using the rolling circle amplification (RCA) method. We use sensitive induction detection techniques in order to measure the ACS response. The DNA is amplified via RCA to generate RCA coils with a specific size that is dependent on the amplification time. After about 75 min of amplification we obtain an average RCA coil diameter of about 1 µm. We determine a theoretical limit of detection (LOD) in the range of 11 attomole (corresponding to an analyte concentration of 55 fM for a sample volume of 200 µL) from the ACS dynamic response after the MNPs have bound to the RCA coils and the measured ACS readout noise. We also discuss further possible improvements of the LOD.


Magnetic multi-core particles

AC susceptometry

Magnetic nanoparticles

RCA coil

Differential induction coil


Fredrik Ahrentorp

Acreo Swedish ICT AB

Jakob Blomgren

Acreo Swedish ICT AB

Christian Jonasson

Acreo Swedish ICT AB

Anna Sarwe

Acreo Swedish ICT AB

Sobhan Sepehri

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Emil Eriksson

Chalmers, Microtechnology and Nanoscience (MC2)

Alexei Kalaboukhov

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Aldo Jesorka

Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry

Dag Winkler

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Justin Schneiderman

University of Gothenburg

MedTech West

Mats Nilsson

Stockholm University

Jan Albert

Karolinska University Hospital

Teresa Zardán Gómez de la Torre

Uppsala University

Maria Strømme

Uppsala University

Christer Johansson

Acreo Swedish ICT AB

Journal of Magnetism and Magnetic Materials

0304-8853 (ISSN)

Vol. 427 14-18

Nanometrology Standardization Methods for Magnetic Nanoparticles (NANOMAG)

European Commission (EC) (EC/FP7/604448), 2013-11-01 -- 2017-10-31.

Subject Categories

Analytical Chemistry

Other Physics Topics



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