How Actuated Particles Effectively Capture Biomolecular Targets
Alexander van Reenen, Arthur M. de Jong, and Menno W.J. Prins
Anal. Chem., Just Accepted
Publication Date (Web): February 13, 2017
Particles are widely used in bioanalytical methods to capture molecular targets, because of their high surface-to-volume ratio and adaptable surface functionalization. In this paper, a comprehensive study is reported of the effectiveness of protein capture by actuated magnetic particles. Association rate constants are quantified in experiments as well as in Brownian dynamics simulations, for different particle actuation configurations. The data reveal how the association rate depends on the particle velocity, the particle density, and particle assembly characteristics. Interestingly, single particles appear to exhibit target depletion zones near their surface, caused by the high density of capture molecules. The depletion effects are even more limiting in case of high particle densities. The depletion effects are overcome and protein capture rates enhanced by applying dynamic particle actuation, resulting in an increase of association rate constants by up to two orders of magnitude.