Nano-antibody aiming at procalcitonin and application thereof

The invention relates to the technical field of biomedicines and clinical diagnosis and discloses a novel nano-antibody aiming at procalcitonin (PCT), a coding sequence of the novel nano-antibody andapplication of the novel nano-antibody to diagnosis. According to the novel nano-antibody provided by the invention, camels are immunized by utilizing the procalcitonin to obtain a high-quality nano-antibody gene library; then an enzyme-coupled plate is coated with the PCT to display a correct space structure of protein; the PCT is used as an antigen for screening a camel heavy-chain antibody bacteriophage display gene library, so that a nano-antibody gene aiming at the PCT is obtained; then the gene is transformed into escherichia coli and a nano-antibody strain which can be efficiently expressed in the escherichia coli is established. According to the novel nano-antibody provided by the invention, two different antigen epitopes, which can be combined with the nano-antibody, in the PCT are finally determined, and