A portable point-of-care device for rapid and sensitive detection of acute SARS-CoV-2 infections.
The COVID-19 pandemic has infected over 40 million people worldwide as of mid-October 2020, causing more than 1 million deaths. Up to 50-80% of transmissions occur from asymptomatic patients. Current tests can have a turnaround time of hours or even days, as well as a high percentage of false negatives. Many tests require that patients come to collection sites, where the risk of transmission is high. Timely, accurate, and accessible testing is required to properly quarantine infected individuals and limit transmission.
The technology is a portable diagnostic test that accepts nasopharyngeal and saliva samples to provide detection of SARS-CoV-2. The test has a 20-minute turnaround time and is highly sensitive and specific, making it faster, and more resistant to false negatives in comparison to current diagnostic tests.
Dr. Wang developed a test and microfluidic device to detect and quantify SARS-CoV2 nucleocapsid antigen. Antibody-coupled magnetic beads in independent microwells immobilize patient sample antigens. Secondary detection by a promoter complex couples the antigen to a platinum nanoparticle (PtNP). H2O2 is applied, and the PtNPs convert this to H2O and O2. This leads to microbubble formation.
Wells in the immobilizing array separate the microbubbles, enabling a digital signal readout. A standard smartphone acquires an image of the microbubbles through a readout window on the device. An associated app interprets the image and supplies a “positive” or “negative” readout.
Dr. Wang has founded a start-up company called Instanosis Inc. to commercialize the highly sensitive platform point of care diagnostic technology. Download the Instanosis Executive Summary
and Instanosis Pitch Deck
- Detection of very small amounts of antigen early in acute infections, with limit of detection similar to molecular methods
- >90% sensitivity and >90% specificity for SARS-CoV-2 antigen
- Rapid 20 minute assay runtime
- Smartphone and self-test compatible
- Portable, minimizing the risk of transmission associated with standard collection sites
- Test can be used by nonprofessionals
- Platform adaptable for detecting other emerging pathogens and diseases.
The figure depicts a positive (left) and negative (right) test result. The reaction of H2O2 and the platinum nanoparticles with antigen bound to them causes microbubbles, indicating a positive result. This reaction does not occur when there is no antigen, so the negative result does not have microbubbles.
Stage of Technology:
- US Provisional Filed
- PCT Patent Application for Platform Technology: WO2020056110A1