Immunoassays using hydrogel microparticles for multiplex detection-enabled shape-coded array

Suspension arrays for protein-based assays have been developed using shape-coded poly(ethylene glycol)(PEG) hydrogel microparticles to overcome the problems with current systems which use color-coded rigid microparticles. In this study, we fabricated various shapes of PEG hydrogel microparticles. PEG hydrogel microparticles were photo-crosslinked with the specific amount of acrylic acid to provide functional groups that enables protein immobilization via EDC/NHS method in the PEGDA (poly(ethyleneglycol) diacrylate, Mw575) precursor. After that, immunoglobulin G(IgG) or immunoglobulin M(IgM) species of primary antibody, were chemically bonded on the surface of the hydrogel microparticles with different shapes and sizes. Then, we captured specific binding molecules. The advantages of this technique are facile recognition of different type of antibodies by the shapes and sizes of the hydrogel particles, and the simple process of particle preparation by photopatterning.