Bead traps in capillary-driven microfluidics for fluorescence immunoassays

Polymeric microspheres represent an important class of components for biological assays because they can be fabricated from many materials, with well-controlled diameters from nanometers to hundreds of micrometers and flinctionalized with biomolecules. However, the incorporation of such microspheres inside microfluidic chips remains a challenge in particular when reproducibility and mass fabrication play an important role. We design and demonstrate how bead traps can assemble defined patterns of 10 uin-polystyrene microspheres in capillary-driven microfluidic chips and show the applicability of bead traps in the context of fluorescence immunoassays.