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

Abstract 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 × 380 μm2 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.