Application of printable antibody ink for solid-phase immobilization of ABO antibody using photoactive hydrogel for surface plasmon resonance imaging

Biochips for multiplex blood typing through surface plasmon resonance imaging (SPRi) readout have been previously reported based on arrays of red blood cell (RBC) specific ABO antibodies (Abs). Although conventional surfaces, such as CM-dextran, are robust and highly specific, they are time and labor intensive to generate and functionalize. This work investigates the fabrication parameters and performance of printable ink consisting of a photoactive hydrogel precursor and antibody mixture for the fabrication of SPRi array biochip. The solid-phase immobilization of commercially available murine IgM ABO Abs on a SPR sensor chip with a multiplex detection of ABO antigens present on the surface membrane of human RBCs is reported. A quick and simple solid phase immobilization of protein on a SPR sensor chip was attained using the photocrosslinking polymer and microarray printing platform. A high density immobilized probes is obtained which allows high sensitivity, specificity, and surface regeneration. A signal to noise ratio of 22:1 and 25:1 at 5% and 10% immobilized-Ab respectively, is obtained with 5% RBC concentration. The sensor surface can be successfully regenerated for repeated use using DI water. Without loss of function, the Ab-printed chips could be stored up to 3 weeks at 4 °C.