One-Step Immunoassay of Influenza Virus Using Screened Fv-Antibodies and Switching Peptides

Abstract

A one-step immunoassay for influenza A detection was established based on screened Fv-antibodies and switching peptides. The switching peptides were synthesized to bind at the frame regions of Fv-antibodies and they dissociated upon binding of target analytes at Fv-antibodies. As the one-step assay could be performed without washing steps and additional reagents treatments, the assay result could be obtained just by mixing samples within 30 min. In this study, Fv-antibodies specific to the influenza virus were screened from an Fv-antibody library expressed on the outer membrane of E. coli BL21(DE3). From the Fv-antibody library, two Fv-antibodies against influenza A nucleoprotein were selected and produced as soluble proteins. The two produced Fv-antibodies specific to the Influenza nucleoprotein had binding constants of 211 and 497 nM. The diagnostic potential of the one-step immunoassay was demonstrated by detecting clinically relevant influenza A and B virus samples. The one-step immunoassay, enabled detection of both influenza A and B.