A sample-to-answer quantitative platform for point-of-care testing of biochemical markers in whole blood

Point-of-care quantitative detection of biochemical markers has broad applications in resource-limited settings. However, current challenges including difficulty in sample preparation and limitation in result quantitation make point-of-care detection platforms failed to achieve fully sample-to-answer detection or meet the clinical quantitative demands. Here, we developed a novel point-of-care platform to realize fully sample-to-answer biochemical marker quantitation in whole blood. Our platform integrated a plasma separation module and a detection module. The plasma separation module contained a plasma separation strip could rapidly separate the plasma from whole blood samples by lateral flow. The detection module generated a colorimetric signal which could be quantified by the smartphone ambient light sensor (ALS) in an equipment-free manner. As a proof-ofconcept, two hepatobiliary disease-associated markers, total bilirubin (TBil) and direct bilirubin (DBi1), were detected from whole blood to quantitative result. The quantitative performance for clinical samples was highly consistent with the well-established clinical chemistry analyzer. Our platform exhibited remarkable advantages of significant portability ( < 40 g), low cost ( < $5), rapidity ( < 5 min), instrument-free, high sensitivity ( < 1 mu M), and accuracy (89.5 % for TBil, 94.7 % for DBi1), which showed up a great potential for biochemical markers detection in resource-limited settings.