A Fluorescence Immunochromatographic Assay Using Europium (III) Chelate Microparticles for Rapid, Quantitative and Sensitive Detection of Creatine Kinase MB

The isoenzyme creatine kinase MB is very important for diagnosis of acute myocardial infarction (AMI). Some CK-MB immunoassays are sensitive, accurate and available for clinical application, but they are expensive and time-consuming procedures. Furthermore, conventional fluorescence immunochromatographic assays (FL-ICAs) have suffered from background fluorescence interference and low analytical sensitivity. A rapid and simple FL-ICA with Eu (III) chelate polystyrene microparticles was developed to determine CK-MB in 50uL serum samples using a portable test strip reader by measuring the fluorescence peak heights of the test line (H-T) and the control line (H-C) in 12 min. The assay was reliable with a good correlation coefficient between H-T/H-C ratio and CK-MB concentration in samples. A linear range was 0.85-100.29 ng/mL for CK-MB, and the LOD was 0.029 ng/mL. The intra- and inter-assay coefficients of variation (CV) were both < 10 % and the average recoveries were from 90.17 % -112.63 % for CK-MB. The system performed well in interference experiments. Furthermore, a highly significant correlation (r = 0.9794, P < 0.001) between this method and the commercially available bioM,rieux mini VIDAS system were attained for measuring 120 CK-MB samples. These results indicated that the Eu (III) chelate microparticles-based FL-ICA is simple, fast, highly sensitive, reliable, and reproducible for point-of-care testing of CK-MB concentrations in serum.