Abstract: The invention provides a set of novel Single domain VHH antibodies against SARS-CoV-2 (SEQ ID N? 1-6) and their use to detect and neutralize the wild type virus.

Abstract: One-step rapid gradient method for rapid generation of nanoantibodies (HHV) against any antigen. Where the method comprises the separation of nanoantibodies against a specific antigen from a nanoantibody expression library through the following steps: (a) binding the antigen of interest to beads made of protein-binding polymers (b) incubating the microorganisms of the expression library with the pearls of stage (a), (c) placing the beads of step (b) in a tube with an inert medium with a density greater than or equal to 1 g/mL and centrifuge for 45 s to 2 minutes at a rate between 150 and 250 g; d) discarding the upper fraction and supernatant with the free microorganisms, and obtain the beads with the linked microorganisms, which correspond to those that express HHV that recognizes the antigen.