Enzyme-linked immunosorbent assay using thin-layered microfluidics with perfect capture of the target protein

We developed a process for enzyme-linked immunosorbent assay on a glass microchip via the use of a thin-layered microfluidic channel. This channel possesses a high aspect ratio (width/depth ∼200) and has an antibody layer immobilized directly on the channel surface. A depth of several microns and an excessive width and length (mm scale) of the channel provide a large-volume capacity (10² nL) and maximum capture efficiency of the analyte for a high level of detection sensitivity (10² pg mL⁻¹). The developed reusable immunosensor has demonstrated high-performance characteristics by requiring less than 50 μL of sample and providing analysis in less than 25 min. This new method could impact the development of point-of-care devices for biomedical applications.