Characterization of binding of magnetic nanoparticles to rolling circle amplification products by turn-on magnetic assay
Artikel i vetenskaplig tidskrift, 2019

The specific binding of oligonucleotide-tagged 100 nm magnetic nanoparticles (MNPs) to rolling circle products (RCPs) is investigated using our newly developed differential homogenous magnetic assay (DHMA). The DHMA measures ac magnetic susceptibility from a test and a control samples simultaneously and eliminates magnetic background signal. Therefore, the DHMA can reveal details of binding kinetics of magnetic nanoparticles at very low concentrations of RCPs. From the analysis of the imaginary part of the DHMA signal, we find that smaller MNPs in the particle ensemble bind first to the RCPs. When the RCP concentration increases, we observe the formation of agglomerates, which leads to lower number of MNPs per RCP at higher concentrations of RCPs. The results thus indicate that a full frequency range of ac susceptibility observation is necessary to detect low concentrations of target RCPs and a long amplification time is not required as it does not significantly increase the number of MNPs per RCP. The findings are critical for understanding the underlying microscopic binding process for improving the assay performance. They furthermore suggest DHMA is a powerful technique for dynamically characterizing the binding interactions between MNPs and biomolecules in fluid volumes.

biomolecular dynamics

binding kinetics


rolling circle amplification product


differential homogenous magnetic assay

magnetic nanoparticle


Sobhan Sepehri

Chalmers, Mikroteknologi och nanovetenskap, Kvantkomponentfysik

Björn Agnarsson

Chalmers, Fysik, Biologisk fysik

Teresa Zardán Gómez De La Torre

Uppsala universitet

Justin Schneiderman

Chalmers, Mikroteknologi och nanovetenskap, Kvantkomponentfysik

Jakob Blomgren

RISE Research Institutes of Sweden

Aldo Jesorka

Chalmers, Kemi och kemiteknik, Kemi och biokemi

Christer Johansson

Chalmers, Mikroteknologi och nanovetenskap

Mats Nilsson

Stockholms universitet

Jan Albert

Karolinska Institutet

Maria Strømme

Uppsala universitet

Dag Winkler

Chalmers, Mikroteknologi och nanovetenskap, Kvantkomponentfysik

Alexei Kalaboukhov

Chalmers, Mikroteknologi och nanovetenskap, Kvantkomponentfysik


20796374 (eISSN)

Vol. 9 3 109

Bärbar influensa diagnostic "FLU-ID"

Stiftelsen för Strategisk forskning (SSF) (SBE13-0125), 2014-06-01 -- 2020-12-31.

Stiftelsen för Strategisk forskning (SSF) (SBE13-0125), 2021-01-01 -- 2021-03-31.


Nanovetenskap och nanoteknik


Biokemi och molekylärbiologi


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