Enhancement of lateral flow assay performance by electromagnetic relocation of reporter particles


Lateral flow assays (LFAs) are a widely-used point-of care diagnostic format, but suffer from limited analytical sensitivity, especially when read by eye. It has recently been reported that LFA performance can be improved by using magnetic reporter particles and an external magnetic field applied at the test line. The mechanism of sensitivity/performance enhancement was suggested to be concentration/retardation of reporter particles at the test line. Here we demonstrate an additional mechanism of particle relocation where reporter particles from the lower depths of the translucent LFA strip relocate to more-visible locations nearer to the top surface, producing a more visible signal. With a magnetic field we observed an improvement in sensitivity of human chorionic gonadotropin (hCG) detection from 1.25 ng/mL to 0.31 ng/mL. We also observed an increase of the color intensity per particle in test lines when the magnetic field was present.



Magnetic fields, Magnets, Enzyme-linked immunoassays, 3D printing, Chorionic gonadotropin, Electromagnetics, Nitrocellulose, Visual signals


Copyright 2018 PLoS ONE. Recommended citation: Jacinto, Maria Jo鉶, Jo鉶 RC Trabuco, Binh V. Vu, Gavin Garvey, Mohammad Khodadady, Ana M. Azevedo, Maria Raquel Aires-Barros et al. "Enhancement of lateral flow assay performance by electromagnetic relocation of reporter particles." PloS one 13, no. 1 (2018): e0186782. DOI: 10.1371/journal.pone.0186782. URL: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0186782. Reproduced in accordance with the original publisher's licensing terms and with permission from the authors.