TY - JOUR

T1 - Point-of-need detection of pathogen-specific nucleic acid targets using magnetic particle spectroscopy

AU - Rösch, Enja Laureen

AU - Zhong, Jing

AU - Lak, Aidin

AU - Liu, Zhe

AU - Etzkorn, Markus

AU - Schilling, Meinhard

AU - Ludwig, Frank

AU - Viereck, Thilo

AU - Lalkens, Birka

N1 - Funding Information: Funding: This work was supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy – EXC-2123 QuantumFrontiers – 390837967, the DFG Research Training Group 1952 Metrology for Complex Nanosystems, ZH 782/1-1 and “Niedersächsisches Vorab” through “Quantum- and Nano-Metrology (QUANOMET)” initiative within the projects NL-1 (BL) and NL-2 (TV).

PY - 2021/11/15

Y1 - 2021/11/15

N2 - 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.

AB - 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.

KW - Diagnostics

KW - Magnetic nanoparticles

KW - Magnetic particle spectroscopy

KW - Point-of-need

KW - SARS-CoV-2

UR - http://www.scopus.com/inward/record.url?scp=85111639313&partnerID=8YFLogxK

U2 - 10.1016/j.bios.2021.113536

DO - 10.1016/j.bios.2021.113536

M3 - Article

AN - SCOPUS:85111639313

VL - 192

JO - Biosensors and Bioelectronics

JF - Biosensors and Bioelectronics

SN - 0956-5663

M1 - 113536

ER -