An Integrated Centrifugal Microfluidic System for Sample-to-Answer Testing of Allergen-Specific IgE from Whole Blood

Sample-to-answer centrifugal microfluidics enables whole blood sIgE testing. • Euler force-driven siphon valves enable actuator free programmable release. • Backflow-suppressed blood separation stabilizes on-chip immunoassays. • Clinical validation demonstrates sample-to-answer allergen-sIgE detection. Allergen-specific immunoglobulin E (sIgE) detection is essential for the diagnosis and management of type I hypersensitivity diseases. However, conventional enzyme-linked immunosorbent assay (ELISA)-based sIgE assays remain limited by laborious blood pretreatment and bulky analytical instruments, restricting their application in point-of-care testing (POCT). Here, we developed an integrated centrifugal microfluidic system (ICMS) for fully automated sample-to-answer detection of allergen-sIgE directly from whole blood. The platform integrates an optimized on-disc blood separation module with Euler force-driven siphon valving strategy to automate whole blood pretreatment, sequential reagent delivery, mixing, incubation, washing, and colorimetric detection. The optimized separation structure enabled efficient serum extraction while suppressing blood cell backflow. Meanwhile, the Euler force-driven siphon valves with tunable triggering thresholds enabled precise multistep fluid manipulation without external actuators, supporting a reliable automated ELISA workflow. The ICMS comprised eight parallel, independently configurable assay units, enabled completion of the entire workflow within 70   min, and was validated for detecting sIgE against cow’s milk, Dermatophagoides pteronyssinus , and Dermatophagoides farinae . Clinical validation showed good agreement with conventional clinical methods, with a correlation coefficient of R 2 = 0.9813 and an overall grading accuracy of 85.19%. Larger-scale clinical studies are needed to further evaluate the diagnostic performance and clinical applicability of the ICMS. These results demonstrate that the proposed ICMS provides a highly integrated, automated, and reliable sample-to-answer platform for direct whole blood allergen-sIgE detection, showing considerable potential for POCT applications in primary healthcare settings. Download: Download high-res image (205KB) Download: Download full-size image