Rapid, sensitive detection of intact SARS-CoV-2 using DNA nets and a smartphone-linked fluorimeter

We report a single-step, room-temperature, five to ten minute SARS-CoV-2 saliva self-monitoring method that overcomes the limitations of existing approaches through the use of fluorophore-releasing Designer DNA Nanostructures (DDNs) that bind with the multivalent pattern of spike proteins on the exterior intact virions and an inexpensive smartphone-linked, pocket-size fluorimeter, called a “V-Pod” for its resemblance to an Apple AirPod™ headphone case. We characterize the V-Pod fluorimeter performance and the DDN-based assay to demonstrate a clinically relevant detection limit of 10⁴ virus particles/mL for pseudo-typed WT SARS-CoV-2 and 10⁵ virus particles/mL for real pathogenic variants, including Delta, Omicron, and D614g.