Digital and Analog Detection of SARS-CoV-2 Nucleocapsid Protein via an Upconversion-Linked Immunosorbent Assay.

ABSTRACT: The COVID-19 crisis requires fast and highly sensitive tests for the early stage detection of the SARS-CoV-2 virus. For detecting the nucleocapsid protein (N protein), the most abundant viral antigen, we have employed upconversion nanoparticles that emit short-wavelength light under near-infrared excitation (976 nm). The anti-Stokes emission avoids autofluorescence and light scattering and thus enables measurements without optical background interference. The sandwich upconversion-linked immunosorbent assay (ULISA) can be operated both in a conventional analog mode and in a digital mode based on counting individual immune complexes. We have investigated how different antibody combinations affect the detection of the wildtype N protein and the detection of SARS-CoV-2 (alpha variant) in lyse

SUBMITTER: Brandmeier JC 

PROVIDER: S-EPMC10018451 | biostudies-literature | 2023 Mar

REPOSITORIES: biostudies-literature