A Microfluidic Fluorescence Immunoassay Test Card for Rapid Detection of Heart-type Fatty Acid Binding Protein

A kind of easily assembly self-driving test card was developed for the rapid detection and quantification of heart-type fatty acid binding protein (H-FABP) utilizing time-resolved fluorescence microspheres as signal probes. It was easy to make microfluidic channel structures with double-sided adhesive and cut out of test card substrate and cover based on polymethyl methacrylate (PMMA) material by the laser cutting technique. The membrane of polystyrene containing maleic anhydride functional groups was coated on PMMA plate surface by dip-coating method. Furthermore, the capture antibody was immobilized effectively on PMMA surface by covalent binding with maleic anhydride groups. The cover was treated with plasma treatment to improve the hydrophilic ability, so that the liquid could flow smoothly in the microchannel. The whole analysis process could be completed within 10 min. There was a very good linear correlation between response and H-FABP concentration in the range of 0.5−100 ng mL−1 (R2 = 0.9966), and the detection limit was 0.1 ng mL−1 (S/N = 3). The intra-assay precision was less than 10% and the inter-assay precision was less than 15%. This detection method has the advantages such as high sensitivity, fast detection and good accuracy.