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 height H, 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 value H, within the range explored in this study, a region depleted of tracers forms around the patch. When H is not much larger than the radius of the patch, the rate of growth of the depletion zone depends on H; 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.

中文翻译：

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板中几何限制对活性葡萄糖氧化酶微泵附近示踪粒子行为的影响

将表面固定化且具有催化活性的酶片浸入具有相应底物的溶液中，诱导溶液中的流动。这种系统目前被认为是开发可以在微流体装置内自主运行的自供电微泵的一个有前途的方向。在这里，我们研究了限制在高度 H 的平板内对沉积在化学活性葡萄糖氧化酶贴片附近的二氧化硅示踪剂颗粒所表现出的响应的影响，该贴片浸入离子强度非常低的葡萄糖溶液中。无论 H 值如何，在本研究探索的范围内，都会在斑块周围形成一个耗尽示踪剂的区域。当 H 不大于斑块半径时，耗尽区的增长速度取决于 H；有点意外，这种依赖性受葡萄糖浓度的影响。结果在化学活性贴剂的简单模型的背景下进行了讨论。