Single virus fingerprinting by widefield interferometric defocus-enhanced mid-infrared photothermal microscopy

This is the authors' abstract. We don't add key points for this paper.

Label-free spectroscopic detection of single viruses provides component analysis of virus strains. Current methods suffer from low throughput and weak signal contrast of individual virions. Here, we report a widefield interferometric defocus-enhanced mid-infrared photothermal (WIDE-MIP) microscopy for high-throughput fingerprinting of single viruses. WIDE-MIP not only reveals the contents of viral proteins and nucleic acids in single DNA vaccinia viruses and RNA vesicular stomatitis viruses, but also uncovers an enriched β sheet components in DNA varicella-zoster virus proteins. Different nucleic acids signatures of thymine and uracil residue vibrations are also obtained to differentiate DNA and RNA viruses.