Optical detection of infectious SARS-CoV-2 virions by counting spikes

Nanoscale. 2024. Vol. 16. No. 26. P. 12424–12430.

Kudryavtsev D., Mozhaeva V., Ivanov I., Siniavin A., Kalmykov A., Gritchenko A., Khlebtsov B., Wang S., Kang B., Tsetlin V., Balykin V., Melentiev P. N.

Existing methods for the mass detection of viruses are limited to the registration of small amounts of a viral genome or specific protein markers. In spite of high sensitivity, the applied methods cannot distinguish between virulent virus particles and non-infectious virus particle debris. We report an approach to solve this long-standing challenge using the SARS-CoV-2 virus as an example. We show that the wide-field optical microscopy with the state-of-the-art mesoscopic fluorescent labels, formed by a core-shell plasmonic nanoparticle with fluorescent dye molecules in the core-shell being in optical strong coupling condition with the plasmonic nanoparticle, not only rapidly, i.e. in less than 20 minutes after sampling, detects SARS-CoV-2 virions directly in a patient sample without a pre-concentration step, but can also distinguish between infectious and non-infectious virus strains by counting the spikes on the lipid envelope of individual virus particles.

Keywords: нанофотоника, nanophotonics, SARS-CoV-2, SARS-CoV-2, strong optical coupling, сильная оптическая связь