(523f) A Three-Dimensional Microfluidic System Integrated with Surface Plasmon Resonance Microscopy for Immunoassays

We demonstrate the combination of a high-throughput microfluidic device with surface plasmon resonance (SPR) microscopy for quantitative, in situ antibody immobilization. The microfluidic device provides 48 separate flow channels that can be used simultaneously for antibody immobilization and subsequent antibody-antigen interaction analysis. The microfluidic system is made from an elastomeric material and the design is based on a standard 96-well plate. Each well in the system is linked to a second well through a pair of channels that meet to form a single V-shaped microfluidic channel. When the microfluidics system is placed at the sensing surface of the SPR microscope, each channel forms a sensing area of ~ 400 x 400 μm. In the current configuration, 48 microfluidic channels form 48 separate sensing regions. One major advantage of the microfluidic system is that the antibody immobilization process is performed under humid conditions to help retain the activity of the antibody. In addition, SPR microscopy provides quantitative characterization of the immobilization process in real time. We are developing high-throughput immmunoassays based on this integrated system. The presented methods could be extended to probe other biomolecule interactions in a label-free, high-throughput and quantitative way.