Automated Electroosmotic Digital Optofluidics for Rapid and Label-Free Protein Detection.

Abstract

Rapid protein detection is crucial for medical diagnosis, clinical trials, and drug development but often faces challenges in balancing sensitivity with multiplex detection, low reagent consumption, and a short detection time. In this work, we developed an automated and sensitive electroosmotic digital optofluidics (e-DOF) platform for rapid and label-free protein biomarker quantification in microliter blood samples. The hyperspectral computation reveals nanoscale morphology changes caused by target protein capture, eliminating multifarious enzyme-linked labeling. Electroosmosis-driven molecular circulation accelerates the immuno-hybridization, enhancing sensitivity (with a detection limit of 0.21 nM) and reducing the detection time to 15 min, compared to 2-3 h for a traditional enzyme-linked immunosorbent assay. In multiplex detection of hepatitis A and E IgM in 17 clinical samples, the results were completely consistent with clinical trial outcomes. This e-DOF system presents an automated, rapid, and label-free platform for multiplex detection in microliter samples, highlighting potential applications in clinical diagnosis and immunoassay research.