Homogeneous differential magnetic assay
Journal article, 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.

magnetic nanoparticles

rolling circle amplification

homogeneous differential magnetic assay

Brownian relaxation

microfluidics

Author

[Person c64f1c1c-2a00-4249-a51d-c816c9b25aeb not found]

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

[Person 9d09ba8e-cd2f-4ee1-baae-425ab6056ad8 not found]

Uppsala University

[Person 97350f12-7f48-4b1f-a3b8-3540fa9c3cf6 not found]

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

[Person 57b0de32-f60e-4daa-a742-bb30e44b7e6c not found]

RISE Research Institutes of Sweden

[Person 2af99314-01aa-45d2-a482-bafeff83d206 not found]

Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry

[Person cd9e0ca6-9ef1-46dd-815a-4dc4edf93593 not found]

Chalmers, Microtechnology and Nanoscience (MC2)

[Person e08b4830-7904-4264-9dbc-e532a7978bea not found]

Science for Life Laboratory (SciLifeLab)

[Person 89a9ec56-3bc4-4252-be4b-5f90ad4b138d not found]

Karolinska University Hospital

Karolinska Institutet

[Person dc03f7ae-ecd0-4d27-b913-4538656ace26 not found]

Uppsala University

[Person 4793483f-f217-4862-aec9-9f08bdb5ba9f not found]

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

[Person d58d8188-5be0-423a-8abf-551f1a971a8e not found]

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

ACS Sensors

2379-3694 (ISSN)

Vol. 4 9 2381-2388

Point-of care Influenza Diagnostics FLU-ID

Swedish Foundation for Strategic Research (SSF), 2014-06-01 -- 2020-06-30.

Areas of Advance

Nanoscience and Nanotechnology (SO 2010-2017, EI 2018-)

Subject Categories

Analytical Chemistry

Medical Equipment Engineering

Biomedical Laboratory Science/Technology

Nano Technology

Other Industrial Biotechnology

Driving Forces

Innovation and entrepreneurship

Infrastructure

Nanofabrication Laboratory

DOI

10.1021/acssensors.9b00969

More information

Latest update

11/10/2019