Screening of aptamer for p30 protein of African swine fever virus and establishment of electrochemical immunosensor for detection of p30 antibody

Currently, antigen and antibody early detection is an important part in the control of African swine fever. However, traditional detection technologies based on antigen-antibody specific binding face problems such as low sensitivity, difficulty in preparing antibodies, and significant differences between batches of antibodies, which require the search for a new type of diagnostic molecule and detection technology. This study employed magnetic beads-SELEX to identify aptamers that specifically bind to the African swine fever virus (ASFV) p30 protein. The aptamer (p30-1) has high affinity and specificity, with no cross-reactivity to His-tagged or GST tagged proteins. In addition, the thiol-modified aptamer was used to immobilize ASFV p30 protein onto an electrochemical immunosensor constructed with thiol-modified multi-walled carbon nanotubes (S-MWCNTs) and gold nanoparticles (AuNPs). The detection of ASFV p30 monoclonal antibody was carried out using differential pulse voltammetry (DPV), and a standard curve was established. The linear detection range was 0.1 μg/mL-4 μg/mL, with a limit of detection (LOD) of 1.38 μg/mL. This method shows good specificity and reproducibility, enabling effective detection of clinical serum samples and infected animal serum samples. It provides new technical support for the rapid detection of ASFV antibodies.