Nguyen Thai Huu, Pei Renjun, Stojanovic Milan, Lin Qiao
Department of Mechanical Engineering, Columbia University, New York, NY 10027.
Sens Actuators B Chem. 2011 Jul 5;155(1):58-66. doi: 10.1016/j.snb.2010.11.024.
This paper demonstrates and systematically characterizes the enrichment of biomolecular compounds using aptamer-functionalized surfaces within a microfluidic device. The device consists of a microchamber packed with aptamer-functionalized microbeads and integrated with a microheater and temperature sensor to enable thermally controlled binding and release of biomolecules by the aptamer. We first present an equilibrium binding-based analytical model to understand the enrichment process. The characteristics of the aptamer-analyte binding and enrichment are then experimentally studied, using adenosine monophosphate (AMP) and a specific RNA aptamer as a model system. The temporal process of AMP binding to the aptamer is found to be primarily determined by the aptamer-AMP binding kinetics. The temporal process of aptamer-AMP dissociation at varying temperatures is also obtained and observed to occur relatively rapidly (< 2 s). The specificity of the enrichment is next confirmed by performing selective enrichment of AMP from a sample containing biomolecular impurities. Finally, we investigate the enrichment of AMP by either discrete or continuous introduction of a dilute sample into the microchamber, demonstrating enrichment factors ranging from 566 to 686×, which agree with predictions of the analytical model.
本文展示并系统地表征了在微流控装置中使用适配体功能化表面对生物分子化合物的富集。该装置由一个填充有适配体功能化微珠的微腔室组成，并集成了一个微型加热器和温度传感器，以实现通过适配体对生物分子进行热控结合和释放。我们首先提出一个基于平衡结合的分析模型来理解富集过程。然后，以单磷酸腺苷（AMP）和一种特定的RNA适配体作为模型系统，对适配体 - 分析物结合和富集的特性进行了实验研究。发现AMP与适配体结合的时间过程主要由适配体 - AMP结合动力学决定。还获得了在不同温度下适配体 - AMP解离的时间过程，并观察到其相对较快地发生（<2秒）。接下来，通过从含有生物分子杂质的样品中选择性富集AMP来确认富集的特异性。最后，我们研究了通过将稀释样品离散或连续引入微腔室来富集AMP的情况，结果表明富集因子在566至686倍之间，这与分析模型的预测相符。
