Homogeneous differential magnetic assay
Artikel i vetenskaplig tidskrift, 2019

Assays are widely used for detection of various targets, including pathogens, drugs, and toxins. Homogeneous assays are promising for the realization of point-of-care diagnostics as they do not require separation, immobilization, or washing steps. For low concentrations of target molecules, the speed and sensitivity of homogeneous assays have hitherto been limited by slow binding kinetics, time-consuming amplification steps, and the presence of a high background signal. Here, we present a homogeneous differential magnetic assay that utilizes a differential magnetic readout that eliminates previous limitations of homogeneous assays. The assay uses a gradiometer sensor configuration combined with precise microfluidic sample handling. This enables simultaneous differential measurement of a positive test sample containing a synthesized Vibrio cholerae target and a negative control sample, which reduces the background signal and increases the readout speed. Very low concentrations of targets down to femtomolar levels are thus detectable without any additional amplification of the number of targets. Our homogeneous differential magnetic assay method opens new possibilities for rapid and highly sensitive diagnostics at the point of care.

homogeneous differential magnetic assay


Brownian relaxation

magnetic nanoparticles

rolling circle amplification


Sobhan Sepehri

Chalmers, Mikroteknologi och nanovetenskap, Kvantkomponentfysik

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

Science for Life Laboratory (SciLifeLab)

Jan Albert

Karolinska universitetssjukhuset

Karolinska Institutet

Maria Strømme

Uppsala universitet

Dag Winkler

Chalmers, Mikroteknologi och nanovetenskap, Kvantkomponentfysik

Alexei Kalaboukhov

Chalmers, Mikroteknologi och nanovetenskap, Kvantkomponentfysik

ACS Sensors

23793694 (eISSN)

Vol. 4 9 2381-2388

Bärbar influensa diagnostic "FLU-ID"

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

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


Nanovetenskap och nanoteknik


Analytisk kemi

Medicinsk apparatteknik

Annan fysik

Biomedicinsk laboratorievetenskap/teknologi


Annan industriell bioteknik


Innovation och entreprenörskap





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