Label-free electronic detection of thrombin in blood serum by using an aptamer-based sensor
Label-free electronic detection of thrombin in blood serum by using an aptamer-based sensor
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DOI：
10.1002/anie.200500989
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发表时间：
2005-01-01
影响因子：
16.6
通讯作者：
Plaxco, KW
中科院分区：
文献类型：
--
作者：
Xiao, Y;Lubin, AA;Plaxco, KW
适体是根据其结合特异性分子靶标的能力在体外选择的DNA或RNA序列。[1-3]由于新的适体可以很容易地形成和他们的一般令人印象深刻的选择性和亲和力，他们被广泛认为是理想的识别元件的生物传感器应用。[4，5]与该声明一致，适体已用于各种传感技术，[6-11]包括称为“适体信标”的非常有前途的光学方法。适体信标采用大规模的结合诱导的构象变化，以调节共价结合的荧光团的发射。[12]到目前为止，已经报道了针对诸如小分子可卡因[13]和蛋白质达特[14]、Taq DNA聚合酶[15]、血小板衍生生长因子[16]和凝血酶等不同靶点的适体信标。[6]适体信标是快速的，无标记的，并且具有特殊的选择性。[12然而，由于信标是光学方法，因此它们相对于电子感测策略具有若干潜在的缺点。这些包括对通常笨重、昂贵和功率密集的光源、检测器和单色器的要求，对光漂白的敏感性，以及由污染荧光团或猝灭剂引起的潜在错误信号。[18]相比之下，现代微电子技术令人印象深刻的小型化以及电活性标签的相对稳定性和环境不敏感性表明，电子传感器可能会避免许多这些陷阱。[19]然而，先前描述的基于电子适体的传感器需要添加外源性试剂或易受污染物的干扰。例如，虽然通过使用基于石英晶体微天平[10]或表面等离子体共振的适体传感器已经证明了令人印象深刻的灵敏度和检测速度[20]，但这两种方法都容易出现非特异性结合引起的假阳性。类似地，虽然已经报道了适体-凝血酶相互作用的电化学检测，但该方法需要复杂的多步预处理和添加外源性氧化还原标记。[第十一届]
Aptamers are DNA or RNA sequences selected in vitro for their ability to bind specific molecular targets.[1–3] Due to the ease with which novel aptamers can be fashioned and their generally impressive selectivity and affinity, they are widely regarded as ideal recognition elements for biosensor applications.[4, 5] Consistent with this claim, aptamers have been employed in a variety of sensing technologies,[6–11] including a very promising optical approach termed “aptamer beacons”. Aptamer beacons employ a large-scale, binding-induced conformational change in order to modulate the emission of a covalently bound fluorophore.[12] To date, aptamer beacons have been reported for such diverse targets as the small molecule cocaine [13] and the proteins Tat,[14] Taq DNA polymerase,[15] platelet-derived growth factor,[16] and thrombin.[6]Aptamer beacons are rapid, label-free, and exceptionally selective.[12, 17] As beacons are an optical approach, however, they suffer from several potential drawbacks relative to electronic-sensing strategies. These include a requirement for generally bulky, expensive, and power-intensive light sources, detectors, and monochromators, a susceptibility to photobleaching, and potential false signals arising from contaminating fluorophores or quenchers.[18] In contrast, the impressive miniaturization of modern microelectronics and the relative stability and environmental insensitivity of electroactive labels suggest that electronic sensors might avoid many of these pitfalls.[19] Previously described electronic aptamerbased sensors, however, require either the addition of exogenous reagents or are susceptible to interference from contaminants. For example, while impressive sensitivity and detection speed have been demonstrated by using aptamer sensors based on the quartz crystal microbalance [10] or on surface plasmon resonance,[20] both approaches are prone to false positives arising from nonspecific binding. Similarly, while the electrochemical detection of an aptamer–thrombin interaction has been reported, the approach requires complex, multistep preprocessing and the addition of an exogenous redox label.[11]