Construction of three single-chain antibody fragment variable fusion structures for sensitive detection of nucleocapsid protein of Hantaan virus

Three single-chain fragment variable (scFv) fusion structures were constructed for use in rapid and sensitive detection of nucleocapsid protein (NP) of Hantaan virus. The detection of NPs on glass chips was signalized by enzyme labeling or fluorescence dye Cy3, or Cy5 cluster nanoparticles. The sensitivity of the methods with different signal systems was evaluated and compared. The detection limits of scFv-alkaline phosphatase fusion, fluorescence labeling (scFv-Cy3), and nanoparticles labeling (scFv-SBP-streptavidin-nanoparticle) were 0.1 mu g/mL, 1 ng/mL, and 0.1 ng/mL NP, respectively, which were all lower than that in a conventional enzyme-linked immunosorbent assay (ELISA) (1 mu g/mL). Twenty Hantaan virus isolates were detected using the proposed methods.