A Self-Powered, One-Step Chip for Rapid, Quantitative and Multiplexed Detection of Proteins From Pinpricks of Whole Blood

Conventionally the detection of proteins in blood includes several lab-intensive steps. Milliliters of blood collected from patients are processed to separate plasma or serum from blood cells. Standard ELISA approach was further used to quantify the level of protein of interest in multiple 96 well plates, each well allowing only one protein detection. Here, an automated, self-powered chip based on lateral flow immunoassay for rapid, quantitative, and multiplex protein detection from pinpricks of whole blood is described. The device incorporates on-chip purification of blood plasma by employing inertial forces to focus blood cells away from the assay surface, where plasma proteins are captured and detected on antibody “barcode” arrays. Power is supplied from the capillary action of a piece of adsorbent paper, and sequentially drives, over a 40 minute period, the four steps required to capture serum proteins and then develop a multiplex immunoassay. An 11 protein panel is assayed from whole blood, with high sensitivity and high reproducibility. This inexpensive, self-contained, and easy to operate chip provides a useful platform for point-of-care diagnoses, particularly in resource-limited settings.