Point-of-need detection of pathogen-specific nucleic acid targets using magnetic particle spectroscopy

authored by
Enja Laureen Rösch, Jing Zhong, Aidin Lak, Zhe Liu, Markus Etzkorn, Meinhard Schilling, Frank Ludwig, Thilo Viereck, Birka Lalkens
Abstract

The ongoing COVID-19 pandemic stresses the need for widely available diagnostic tests for the presence of SARS-CoV-2 in individuals. Due to the limited availability of vaccines, diagnostic assays which are cheap, easy-to-use at the point-of-need, reliable and fast, are currently the only way to control the pandemic situation. Here we present a diagnostic assay for the detection of pathogen-specific nucleic acids based on changes of the magnetic response of magnetic nanoparticles: The target-mediated hybridization of modified nanoparticles leads to an increase in the hydrodynamic radius. This resulting change in the magnetic behaviour in an ac magnetic field can be measured via magnetic particle spectroscopy (MPS), providing a viable tool for the accurate detection of target nucleic acids. In this work we show that single stranded DNA can be detected in a concentration-dependent manner by these means. In addition to detecting synthetic DNA with an arbitrary sequence in a concentration down to 500 pM, we show that RNA and SARS-CoV-2-specific DNA as well as saliva as a sample medium can be used for an accurate assay. These proof-of-principle experiments show the potential of MPS based assays for the reliable and fast diagnostics of pathogens like SARS-CoV-2 in a point-of-need fashion without the need of complex sample preparation.

External Organisation(s)
Technische Universität Braunschweig
Type
Article
Journal
Biosensors and Bioelectronics
Volume
192
ISSN
0956-5663
Publication date
15.11.2021
Publication status
Published
Peer reviewed
Yes
ASJC Scopus subject areas
Biotechnology, Biophysics, Biomedical Engineering, Electrochemistry
Sustainable Development Goals
SDG 3 - Good Health and Well-being
Electronic version(s)
https://doi.org/10.1016/j.bios.2021.113536 (Access: Open)