Vertically encoded tetragonal hydrogel microparticles for multiplexed biomolecule detection

Encoded hydrogel particles have drawn many attentions in diagnostics as the particles can be used for high-performance multiplexed assays. Here, we present encoded tetragonal hydrogel microparticles that are comprised of vertically distinct code and probe regions, and incorporated with quantum dots (QDs) in the code regions. By virtue of the particle geometry, particles can be synthesized at a high production rate in vertically stacked micro-flows using hydrodynamic focusing lithography. The particle coding capacity can be largely expanded by changing wavelengths of QDs and the number of code layers. We also demonstrate the multiplexed capability of the particles in a DNA assay.