Bioinspired Ultrafast Trapping of Microbead Array for Digital Immunoassay

We report a bio-inspired self-driven microfluidic chip that provides ultrafast, high-efficiency, high-throughput microbead array for automated digital immunoassay. Inspired by peristome surface of nepenthes, a droplet solution with 4 million biotinylated microbead was directly transported to the tilted array channel where microbeads were trapped by local Laplace pressure and in-depth hydrodynamic force with 85% matrix coverage within only 40s. We demonstrated its application for digital ELISA using affinity - peroxidase complex (APC) and showed an excellent linearity of 98.8%.