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pH-EVD: A pH-Paper-Based Extraction and Visual Detection System for Instrument-Free SARS-CoV-2 Diagnostics
Xiong Ding1, Ziyue Li1, Lori Avery2
1Department of Biomedical Engineering University of Connecticut Health Center 263 Farmington Ave Farmington CT 06030 USA.
Advanced Nanobiomed Research
|April 20, 2022
Summary
A new pH paper method enables rapid, instrument-free detection of SARS-CoV-2, the virus causing COVID-19. This low-cost approach simplifies diagnostics for widespread, onsite testing.
Area of Science:
- Biotechnology
- Molecular Diagnostics
- Point-of-Care Testing
Background:
- The COVID-19 pandemic, caused by SARS-CoV-2, necessitates rapid and accessible diagnostic tools.
- Current detection methods often require extensive sample preparation and specialized equipment, limiting their use in resource-limited settings.
Purpose of the Study:
- To develop an instrument-free method for simultaneous RNA extraction and visual detection of SARS-CoV-2.
- To achieve rapid, reliable, and low-cost COVID-19 diagnostics.
Main Methods:
- A novel pH paper-based approach (pH-EVD) was developed for integrated RNA extraction and visual isothermal amplification.
- Capillary forces were utilized for rapid, equipment-free RNA extraction in under 1 minute.
- Dye-free visual isothermal amplification was performed directly on the pH paper.
Main Results:
- The pH-EVD method achieved a sample-to-answer time of less than 46 minutes.
- It demonstrated consistent detection of 1200 genome equivalents/µL of SARS-CoV-2 in saliva, comparable to RT-qPCR.
- Clinical validation was performed on nasopharyngeal swab and saliva samples using a portable smart cup incubator.
Conclusions:
- The pH-EVD method offers a simple, rapid, reliable, and instrument-free solution for SARS-CoV-2 detection.
- This technology has significant potential for streamlining onsite COVID-19 diagnostics and improving accessibility.
