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

Abstract

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 (HT) and the control line (HC) in 12 min. The assay was reliable with a good correlation coefficient between HT/HC 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 bioMérieux 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. Graphical Abstract ᅟ.

Rapid and Sensitive Lateral Flow Immunoassay Method for Procalcitonin (PCT) Based on Time-Resolved Immunochromatography

“…First, we selected a desirable nitrocellulose (NC) membrane which may best fit the design requirement through the specification provided by manufacturers and the experience from our laboratory team [25,26,27]. Different membranes have different physical and chemical attributes, which affect its capillary flow properties.…”

Europium (III) chelate microparticle-based lateral flow immunoassay strips for rapid and quantitative detection of antibody to hepatitis B core antigen

“…The conjugates of CM-EUs and anti-HBcAg McAb were prepared using a method as described in our previous work with only minor modifications 23 , 24 . In brief, 2 mg of CM-EUs were suspended in 1 mL of activating buffer including sulfo-NHS and EDC with final concentrations of 10 mmol L −1 and 1.25 mmol L −1 , respectively.…”

“…The CM-EUs-based test strip consists of five parts, including the sample pad, conjugate pad, NC membrane, absorbent pad and backing plate. Initially, the sample pad and conjugate pad were pretreated with sample pad treatment buffer and conjugate pad treatment buffer, respectively, as described in our previous work 23 , 24 . The conjugates of CM-EUs with anti-HBcAg McAb and the conjugates of CM-EUs with RIgG were diluted and mixed in antibody dilution buffer with final concentrations of CM-EUs of 0.5 g L −1 and 0.025 g L −1 , respectively.…”

“…In recent years, the lateral flow immunoassay (LFIA), a well-established and accepted point-of-care testing (POCT) technique, has been used to develop quantitative fluorescent strips using fluorescent reporters including colloidal gold, fluorescent dyes, quantum dots and lanthanide chelates 19 – 22 . In our previous studies, we reported that LFIA based Polystyrene Eu (III) chelate microparticles could be used for quantitative detection of AFP and creatine kinase MB 23 , 24 . The LFIA system not only takes advantage of the simplicity, rapidity and relatively low cost of conventional lateral flow strips, but also possesses a high sensitivity afforded by the polystyrene Eu (III) chelate microparticles owing to their characteristic narrow band emission and large Stokes shift 25 .…”

Rapid and quantitative detection of urinary Cyfra21-1 using fluorescent nanosphere-based immunochromatographic test strip for diagnosis and prognostic monitoring of bladder cancer

“…particles can be used as label for immunochromatographic assay. Among these, fluorescent labels offer high sensitivity and time-resolved fluorescent immunoassay by using lanthanide elements such as europium (Eu) and samarium (Sm) in which fluorofores possess a longer fluorescence lifetime, narrow emission spectra, large stokes shifts and outstanding photostabilities [22][23][24][25]. The quantitative range is directly related to the number of specific proteins involved in the reaction system, and the performance index is much higher than other rapid detection techniques [26][27][28].…”