Paper-Based Test for Rapid On-Site Screening of SARS-CoV-2 in Clinical Samples.

Wen Ren,Joseph Irudayaraj

doi:10.3390/bios11120488

Wen Ren, Joseph Irudayaraj

Open Access

https://doi.org/10.3390/bios11120488

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Abstract

Detection methods for monitoring infectious pathogens has never been more important given the need to contain the spread of the COVID-19 pandemic. Herein we propose a highly sensitive magnetic-focus-enhanced lateral flow assay (mLFA) for the detection of SARS-CoV-2. The proposed mLFA is simple and requires only lateral flow strips and a reusable magnet to detect very low concentrations of the virus particles. The magnetic focus enhancement is achieved by focusing the SARS-CoV-2 conjugated magnetic probes in the sample placed in the lateral flow (LF) strips for improved capture efficiency, while horseradish peroxidase (HRP) was used to catalyze the colorimetric reaction for the amplification of the colorimetric signal. With the magnetic focus enhancement and HRP-based amplification, the mLFA could yield a highly sensitive technology for the recognition of SARS-CoV-2. The developed methods could detect as low as 400 PFU/mL of SARS-CoV-2 in PBS buffer based on the visible blue dots on the LF strips. The mLFA could recognize 1200 PFU/mL of SARS-CoV-2 in saliva samples. With clinical nasal swab samples, the proposed mLFA could achieve 66.7% sensitivity and 100% specificity.

Highlights

The effect of the recent COVID-19 pandemic has brought forth tremendous infections and deaths among other negative influences on human life and economics
It should be noted that the list of the new variants of SARS-CoV-2 is on the rise
We propose an LFA-based detection strategy termed as magnetic-focus-enhanced lateral flow assay with greatly improved sensitivity while retaining the simplicity

Summary

Introduction

The effect of the recent COVID-19 pandemic has brought forth tremendous infections and deaths among other negative influences on human life and economics. The increasing number of vaccinations brings a shimmering hope to control the pandemic. The SARS-CoV-2 virus, which causes COVID-19, exhibits a high mutation rate and generated multiple variants. Some of the variants could spread faster, induce more severe illness and even breakthrough infection with the vaccinated population, such as the Delta variant. It should be noted that the list of the new variants of SARS-CoV-2 is on the rise. In addition to the development of effective vaccines and virus mutation, technologies for infection monitoring to control the spread of SARS-CoV-2 is critical for saving lives and resources

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