Development of a fluorescence immunochromatographic assay based on quantum dot labeling for detection of pseudorabies virus gB protein.

Pseudorabies virus (PRV) remains a major threat to the global swine industry, and the development of rapid, sensitive, and reliable diagnostic methods is critical for effective disease control. In this study, we developed and validated a quantum dot-based fluorescent immunochromatographic strip assay (QDs-FICS) for the rapid detection of PRV glycoprotein B (gB). Recombinant PRV gB protein was expressed in HEK293F cells and used as the immunogen to generate monoclonal antibodies. An optimal antibody pair was screened using a double-antibody sandwich ELISA and subsequently employed to construct the fluorescent immunochromatographic assay. The performance of the assay was systematically evaluated in terms of specificity, sensitivity, and stability. Qualitative spike-in validation in PRV-negative porcine serum was further performed to verify its practical applicability in clinical samples. The results demonstrated that the QDs-FICS exhibited high specificity without cross-reactivity to other viral proteins, high sensitivity with a visual limit of detection of 102.5 TCID50/100 μL, and satisfactory stability during storage. Moreover, the assay could be completed within a short time and required minimal operational procedures. Collectively, the QDs-based fluorescent immunochromatographic assay established in this study provides a rapid, sensitive, and reliable tool for PRV antigen detection, and has strong potential for application in clinical diagnosis, epidemiological surveillance, and on-site detection of pseudorabies.