Peptide beacon integrated planar waveguide sensor for low-cost, rapid, and highly sensitive detection of Covid-19

Soumya Pratap Tripathy, a PhD student in the Molecular Machines group, will deliver this talk as part of the Nano Explorations event series hosted by MIT.nano. This talk is virtual, free, and open to the public.

The novel coronavirus SARS-CoV-2 continues to pose a significant global health threat. Along with vaccines and targeted therapeutics, there is a critical need for rapid diagnostic solutions. In this work, we employ a deep learning-based protein design to engineer molecular beacons that function as conformational switches for high sensitivity detection of the SARS-CoV-2 spike protein receptor-binding domain (S-RBD). The beacons contain two peptides, together forming a heterodimer, and a binding ligand between them to detect the presence of S-RBD.

In the absence of S-RBD (OFF), the peptide beacons adopt a closed conformation that opens when bound to the S-RBD and produces a fluorescence signal (ON), utilizing a fluorophore-quencher pair at the two ends of the heterodimer stems. We integrated these beacons on a planar waveguide-based fluorescence sensor to construct a point-of-care diagnostic platform for SARS-CoV-2. The device can detect the S-RBD with limits of detection (LoD) in the sub-femtomolar range. We envision that the platform will be a rapid at-home diagnostic device in the future.