Assessment of protein binding with magnetic microrobots in fluid

For applications such as targeting therapeutic nanocarriers to specific tissues, as well as for the more general problem of assessing binding affinity between proteins, it is important to discover tools which may be used for both micromanipulation as well as force microscopy. In this work, we measure picoscale forces using microscale robots, using antibody-coated microbead probes as an interface. We develop a model for a detailed understanding of the relationship between robot velocity and applied force, and apply this to the measurement of binding forces between antibody-coated beads and protein-coated glass slides. We also verify binding between specific antibody/protein combinations relative to untargeted control combinations, and we measure the rate at which this binding occurs. This offers a truly novel technique for measuring binding forces between proteins.