The capture of antibodies by antibody-binding proteins for ABO blood typing using SPR imaging-based sensing technology

In this study, a wavelength-interrogated surface plasmon resonance imaging-based immunosensor was developed for ABO blood typing. To construct the immunosensor, the detection line array was formed by the site-directed immobilization of blood group antibodies on SPR chip modified with antibody-binding proteins. Red blood cell (RBC) samples were flowed into the multichannel flow cell that was orthogonal to the detection line arrays. By serially analyzing the interaction between RBCs, antibody A, and antibody B through the observed changes in the resonance dip, blood typing of four RBC samples was achieved in a single run. Detailed investigations focused on optimizing the conditions that affected the efficiency and sensitivity of immunoassay. Under the optimized conditions, the RBC samples were appropriately grouped in less than 1 h, including chip modification time. The lowest detection limit for RBC-A and RBC-B was 2×10 6 cells/ml. The immunosensor developed through this study provided a simple, rapid, high-throughput, and sensitive immunology strategy for classification of ABO blood group.