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Sub-picomolar lateral flow antigen detection with two-wavelength imaging of composite nanoparticles
- Publication Year :
- 2022
- Publisher :
- Elsevier, 2022.
-
Abstract
- Lateral flow tests, commonly based on metal plasmonic nanoparticles, are rapid, robust, and low-cost. However, improvements in analytical sensitivity are required to allow detection of low-abundance biomarkers, for example detection of low antigen concentrations for earlier or asymptomatic diagnosis of infectious diseases. Efforts to improve sensitivity often require changes to the assay. Here, we developed optical methods to improve the sensitivity of absorption-based lateral flow tests, requiring no assay modifications to existing tests. We experimentally compared five different lock-in and subtraction-based methods, exploiting the narrow plasmonic peak of gold nanoparticles for background removal by imaging at different light wavelengths. A statistical framework and three fitting models were used to compare limits of detection, giving a 2.0-5.4-fold improvement. We then demonstrated the broad applicability of the method to an ultrasensitive assay, designing 530 nm composite nanoparticles to increase the particle volume, and therefore light absorption per particle, whilst retaining the plasmonic peak to allow background removal and without adding any assay steps. This multifaceted, modular approach gave a combined 58-fold improvement in the fundamental limit of detection using a biotin-avidin model over 50 nm gold nanoparticles with single-wavelength imaging. Applying to a sandwich assay for the detection of HIV capsid protein gave a limit of detection of 170 fM. Additionally, we developed an open-source software tool for performing the detection limit analysis used in this work.
- Subjects :
- Bioinformatics
Biomedical Engineering
Biophysics
Biotin
Metal Nanoparticles
Biosensing Techniques
Imaging
0903 Biomedical Engineering
Limit of Detection
Electrochemistry
ASSAY
Nanoscience & Nanotechnology
Lateral flow
Science & Technology
1007 Nanotechnology
Chemistry, Analytical
General Medicine
PERFORMANCE
Chemistry
Biosensors
Biotechnology & Applied Microbiology
Physical Sciences
PAPER
Science & Technology - Other Topics
Nanoparticles
Gold
Life Sciences & Biomedicine
0301 Analytical Chemistry
Biotechnology
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Accession number :
- edsair.doi.dedup.....aaa0610b68cd47fe696a1ea3b1ffc1c1