Coding and decoding stray magnetic fields for multiplexing kinetic bioassay platform

Yuan Liu, Gungun Lin, Yinghui Chen, Ingolf Mönch, Denys Makarov, Bradley J. Walsh, Dayong Jin*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)


Polymer microspheres can be fluorescently-coded for multiplexing molecular analysis, but their usage has been limited by fluorescent quenching and bleaching and crowded spectral domain with issues of cross-talks and background interference. Each bioassay step of mixing and separation of analytes and reagents require off-line particle handling procedures. Here, we report that stray magnetic fields can code and decode a collection of hierarchically-assembled beads. By the microfluidic assembling of mesoscopic superparamagnetic cores, diverse and non-volatile stray magnetic field response can be built in the series of microscopic spheres, dumbbells, pears, chains and triangles. Remarkably, the set of stray magnetic field fingerprints are readily discerned by a compact giant magnetoresistance sensor for parallelised screening of multiple distinctive pathogenic DNAs. This opens up the magneto-multiplexing opportunity and could enable streamlined assays to incorporate magneto-mixing, washing, enrichment and separation of analytes. This strategy therefore suggests a potential point-of-care testing solution for efficient kinetic assays.

Original languageEnglish
Pages (from-to)4561-4571
Number of pages11
JournalLab on a Chip
Issue number24
Publication statusPublished - 21 Dec 2020
Externally publishedYes

Bibliographical note

Funding Information:
Authors acknowledge the financial supports from the Australian Research Council (ARC) Industry Transformational Research Hub Scheme (grant IH150100028), the National Health and Medical Research Council (NHMRC) Fellowship Scheme (GNT1160635 – G.L.), China Scholarship Council (201608140100 – Y. L.), the German Research Foundation (DFG) (Grant MA 5144/14-1 – I. M. and D. M.).

Publisher Copyright:
© The Royal Society of Chemistry.

Copyright 2021 Elsevier B.V., All rights reserved.


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