Abstract

Temperature sensing is a promising method of enhancing the detection sensitivity of lateral flow immunoassay (LFIA) for point-of-care testing. A temperature increase of more than 100 °C can be readily achieved by photoexcitation of reporters like gold nanoparticles (GNPs) or colored latex beads (CLBs) on LFIA strips with a laser power below 100 mW. Despite its promise, processes involved in the photothermal detection have not yet been well-characterized. Here, we provide a fundamental understanding of this thermometric assay using non-fluorescent CLBs as the reporters deposited on nitrocellulose membrane. From a measurement for the dependence of temperature rises on the number density of membrane-bound CLBs, we found a 1.3-fold (and 3.2-fold) enhancement of the light absorption by red (and black) latex beads at 520 nm. The enhancement was attributed to the multiple scattering of light in this highly porous medium, a mechanism that could make a significant impact on the sensitivity improvement of LFIA. The limit of detection was measured to be 1 × 105 particles/mm2. In line with previous studies using GNPs as the reporters, the CLB-based thermometric assay provides a 10× higher sensitivity than color visualization. We demonstrated a practical use of this thermometric immunoassay with rapid antigen tests for COVID-19.

Details

Title
Thermometric lateral flow immunoassay with colored latex beads as reporters for COVID-19 testing
Author
Azuma Terumitsu 1 ; Hui Yuen Yung 2 ; Chen, Oliver Y 2 ; Yuh-Lin, Wang 1 ; Huan-Cheng, Chang 3 

 Academia Sinica, Institute of Atomic and Molecular Sciences, Taipei, Taiwan, ROC (GRID:grid.28665.3f) (ISNI:0000 0001 2287 1366); National Taiwan University, Department of Physics, Taipei, Taiwan, ROC (GRID:grid.19188.39) (ISNI:0000 0004 0546 0241) 
 Academia Sinica, Institute of Atomic and Molecular Sciences, Taipei, Taiwan, ROC (GRID:grid.28665.3f) (ISNI:0000 0001 2287 1366) 
 Academia Sinica, Institute of Atomic and Molecular Sciences, Taipei, Taiwan, ROC (GRID:grid.28665.3f) (ISNI:0000 0001 2287 1366); National Taiwan University of Science and Technology, Department of Chemical Engineering, Taipei, Taiwan, ROC (GRID:grid.45907.3f) (ISNI:0000 0000 9744 5137); National Taiwan Normal University, Department of Chemistry, Taipei, Taiwan, ROC (GRID:grid.412090.e) (ISNI:0000 0001 2158 7670) 
Publication year
2022
Publication date
2022
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2637832880
Copyright
© The Author(s) 2022. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.