Fluorescent immunochromatographic assay for quantitative detection of the foot-and-mouth disease virus serotype O antibody

Abstract

Ultrasensitive and quantitative real-time detection of infectious disease has long been a challenge in prevention and diagnosis of epidemic disease. It's essential to develop a quantitative point-of-care (POC) diagnostic approach. Herein, a fluorescent platform was designed, which was a sandwich type and applied noninfectious virus-like-particles (VLPs) as capture antigen, making the process safer and more efficient. The fluorescent europium microparticles (EuMSs) conjugated with staphylococcal protein-A (SPA), then antibody was bind with SPA and target antibody was further captured by VLPs at test line. The excessive labelled-SPA was captured by rabbit IgG at control line. Specifically, the fluorescent signal intensity at test line and control line was relative to the concentration of the target antibody. Moreover, the fluorescent assay can not only be monitored through fluorescent signal output within 15 min but also be observed under UV light with 5 min. The limit of detection (LOD) for quantitative detection of serotype O antibody against foot-and-mouth disease virus (O-FMDV) in serum was over 60 times more sensitive than conventional colored gold-colloids. Owing to the advantages of sensitivity and specificity, the fluorescent immunochromatographic test strips (ICTSs) would be a potential tool for rapid and sensitive probe for quantitative determination of O-FMDV antibody.