Comparative assessment of oriented antibody immobilization on surface plasmon resonance biosensing

Protein A and protein G are extremely useful molecules for the immobilization of antibodies. However, there are limited comparative reports available to evaluate their immobilization performance for use as biosensors. In this study, a comparative analysis was made of approaches that use protein A and protein G for avian leukosis virus detection. The antibody-protein binding affinities were determined using surface plasmon resonance (SPR) analysis. The immobilization efficiency was obtained by calculating the number of the protein molecular binding sites. The positive influence of sensor response on antigen detection indicates that the amount of immobilized antibody plays a major role in the extent of immobilization. Moreover, the biosensors constructed using both proteins were found to be regenerative. The SPR results from this study suggest that the surfaces of protein G provide a better equilibrium constant and binding efficacy for immobilized antibodies, resulting in enhanced antigen detection.