Capillary microfluidics for immunoassays by integrating 3D printing and pressure-sensitive adhesive

Herein, we present a versatile immunoassay device made by 3D-printed (3DP) multilevel microfluidic chip sealed by an optically clear Pressure-Sensitive Adhesive (PSA). The bioreceptors were effectively immobilized on the PSA. Both colorimetric and fluorescence detection methods were successfully applied by using clear and black photo-curable resins, respectively. The design relied on a 3D retention valve to provide a sequential system for all crucial steps of an immunoassay. By synchronizing the microchannel resistances, 3D retention valve, and suction pressure, reagents were driven and controlled uniquely by the capillary force without any external equipment. The proposed device is cost-effective, self-powered, robust, and ideal for non-expert usersPostprint (published version