A capillary-based chemiluminescence immunoassay system using a charge-coupled device (CCD) camera as detector was established in this paper. The fused quartz capillary was easily activated in one step for immobilizing capture antibody, and the chemiluminescence immunoassay was carried out in the capillary in double-antibody sandwich format. Chemiluminescence signals were recorded by the portable imaging device which was installed with the CCD camera and the results were analyzed through gray intensity. The total cost time, which included not only the time for test but also the time for the preparation of experimental materials, was only 2 h. The immunoassay was performed without any complicated or expensive instruments. The consumption of the sample was only 0.8 μL in one test, which was significantly less than other methods. In this work, C-reactive protein (CRP), as a target, was quantitatively detected from 0.3 to 160.0 μg mL-1 with high specificity and low sample volume. The reproducibility and accuracy were tested in clinic human serum samples and shown good results. Thus, this rapid, easy preparation and using, portable immunoassay system indicated its usefulness as a novel technology platform. Graphical abstract ᅟ.
Keywords: C-reactive protein; Capillary; Immunoassay; Portable imaging device.