Femtosecond laser direct fabrication of micro-grooved textures on a capillary flow immunoassay microchip for spatially-selected antibody immobilization

We successfully demonstrate localized immobilization of antiadiponectin antibodies on superhydrophilic micro-grooved structures in a PMMA (polymethyl methacrylate) capillary flow immunoassay microchip. The microstructures were generated using femtosecond laser machining. Using inkjet printing, droplets of antibody solution only a few tens of picoliters in volume can be immobilized in a 200 x 380 mu m(2) area. The enhanced immobilization was confirmed in a microchip-based luminescent ELISA (enzyme-linked immunosorbent assay). We investigate not only the immobilization performance, but also the optimum conditions for the laser fabrication procedure and the microstructure design. (C) 2016 Elsevier B.V. All rights reserved.