The impact of geometrical confinement in a slab on the behavior of tracer particles near active glucose oxidase micropump

Patches of surface-immobilized and catalytically active enzyme, immersed into a solution with the corresponding substrate, induce flow in the solution. Such systems are currently investigated as a promising direction in the development of self-powered micropumps that could operate autonomously within microfluidic devices. Here, we investigate the influence of confinement, within a slab of heightH, on the response exhibited by silica tracer particles sedimented near a chemically active glucose oxidase patch which is immersed into a glucose solution of very low ionic strength. Irrespective of the valueH, within the range explored in this study, a region depleted of tracers forms around the patch. WhenHis not much larger than the radius of the patch, the rate of growth of the depletion zone depends onH; somewhat surprisingly, this dependence is influenced by the glucose concentration. The results are discussed within the context of a simple model for a chemically active patch.

Automated summary

The study investigates the influence of confinement on the response of silica tracer particles near a chemically active glucose oxidase patch immersed in a glucose solution. A region depleted of tracers forms around the patch regardless of the height H within the explored range. The rate of growth of the depletion zone depends on H when H is not much larger than the patch radius, and this dependence is influenced by the glucose concentration.