A COVID-19 rapid antigen test employing upconversion nanoparticles.

Area of Science:

• Nanotechnology applications in diagnostics
• Optical biosensors
• Point-of-care testing development

Background:

• Existing COVID-19 diagnostic methods (PCR, RAT) have limitations in speed, sensitivity, and accessibility.
• Nanotechnology, specifically upconversion nanoparticles (UCNPs), presents unique optical properties for enhanced detection.
• UCNPs convert near-infrared light to visible light, enabling sensitive optical probes.

Purpose of the Study:

• To explore the use of highly doped UCNPs in lateral flow assays (LFAs) for early COVID-19 diagnosis.
• To develop a rapid, sensitive, and point-of-care diagnostic tool for SARS-CoV-2.
• To establish a benchmark for highly sensitive and quantitative rapid antigen tests (RATs).

Main Methods:

• Development of UCNPs (40% Yb3+/4% Er3+) for integration into LFAs.
• Testing UCNPs-based LFA for detection limits of SARS-CoV-2 antigen and inactivated virus.
• Conducting independent clinical trials in Malaysia and Western Australia.
• Development of the Virulizer device for automated, point-of-care strip reading.

Main Results:

• Achieved a minimum detection concentration of 100 pg/mL for SARS-CoV-2 antigen and 10^5 CCID50/mL for inactivated virus.
• Clinical trials demonstrated at least 100 times greater sensitivity compared to commercial RAT kits.
• Clinical performance showed 100% sensitivity and 91.94% specificity.
• The Virulizer device facilitates automated, quantitative results at the point of care.

Conclusions:

• UCNPs-based LFAs represent a significant advancement in rapid COVID-19 diagnostics.
• This technology offers superior sensitivity and quantitative capabilities for point-of-care testing.
• The developed method sets a new standard for future sensitive antigen detection assays.