Facile fabrication of microsphere-polymer brush hierarchically three-dimensional (3D) substrates for immunoassays.

We propose a facile UV strategy to construct a hierarchically three-dimensional (3D) substrate that comprises a polystyrene (PS) microsphere layer on the cycloolefin polymer (COP) substrate and densely packed hydrophilic polymer brushes grafting from this 3D backbone. This hierarchical substrate gives a high antibody loading capacity and 3D manner of analyte capture, therefore enhancing detection signal while reducing background noise.