Rapid and Versatile Time-Resolved Fluorescent Immunochromatographic Assay (TRFIA) for the Determination of Heparin-Binding Protein

A time-resolved fluorescence immunochromatographic assay (TRFIA) was developed for the point-of-care testing (POCT) of human heparin-binding protein (HBP). HBP monoclonal antibodies were coupled to the surface of fluorescent microspheres loaded with europium (Eu) and its complexes as carriers to prepare and characterize labeled antibodies. TRFIA reagents and conditions were optimized. The detection limit was 2.69 ng/mL, with good linearity in the range of 3.75–60 ng/mL and no apparent cross-reactivity. The intra-batch and inter-batch coefficients of variation were 5.33–8.94% and 7.83–12.22%, respectively. The developed method had universality, accuracy, and sensitivity that well meet the requirements of clinical detection.