A monoclonal antibody-based electrochemical immunosensor for porcine epidemic diarrhea virus

This study reports the development of a novel and highly sensitive electrochemical immunosensor for detecting porcine epidemic diarrhea virus (PEDV). To this end, a unique PEDV spike protein-specific monoclonal antibody (mAb) was generated and evaluated using enzyme-linked immunosorbent assay (ELISA), indirect immunofluorescence assay (IFA), western blot (WB), and flow cytometry. The mAb, classified as an IgG1 subtype in the light chain, recognizes a linear epitope of the PEDV S protein (⁶⁹⁶SVTPCSFSEQAAYVDDDIV⁷¹⁵). Further analysis showed that this epitope (amino acids 696-715) is localized on the surface of the PEDV S protein in the 3D structure. The antibody was then immobilized on the immunosensor to specifically recognize PEDV. A screen-printed electrode (SPE) modified with gold nanoparticles (AuNPs) was prepared and coupled to the PEDV mAb 1G10 via protein A (Pro A) to construct a new PEDV immunosensor. PEDV concentration was quantified by measuring changes in charge transfer resistance after antigen-antibody binding. The proposed immunosensor demonstrated excellent repeatability, stability, and specificity, and was successfully applied to detect PEDV in real samples. KEY POINTS: • Identification of a novel linear epitope (⁶⁹⁶S-V⁷¹⁵) on the PEDV spike protein. • Development of a highly sensitive electrochemical immunosensor for PEDV detection. • The biosensor accurately detected PEDV in clinical pig manure samples.