We developed a fast, simple, label-free method useful for the study of interactions between an antibody (Ab) and antigen based on chronopotentiometric stripping analysis and the catalytic hydrogen evolution reaction. The specific interaction of the Ab, adsorbed at a mercury electrode, with AGR3 protein induced a significant increase in chronopotentiometric peak H in comparison to both the CPS response of the Ab alone and that after incubation with nonspecifically binding proteins. Qualitatively similar results were obtained with another polyclonal antibody specific for AGR2 protein. The demonstrated results, along with previous findings indicate that the proposed technique shows promise as a new option for studying the dynamics, not only of surface-attached antibody-antigen complexes, but also other protein-protein interactions. (C) 2018 Elsevier Ltd. All rights reserved.