Re-engineering aptamers to support reagentless, self-reporting electrochemical sensors.
Re-engineering aptamers to support reagentless, self-reporting electrochemical sensors.
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DOI：
10.1039/b921253a
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发表时间：
2010-03
期刊：
影响因子：
--
通讯作者：
Plaxco KW
中科院分区：
文献类型：
--
作者：
White RJ;Rowe AA;Plaxco KW
基于电化学适体（E-AB）的传感器已成为一种有前途的和多功能的新的生物传感器平台。将适配体-配体相互作用的一般性和特异性与电化学读数的选择性和便利性相结合，这种方法提供了直接在复杂的污染物污染样品中检测各种各样的目标，如全血，食品和粗土壤提取物，而不需要外源试剂或洗涤步骤。这类传感器中的信号传导基于靶诱导的电极结合的探针适体的构象变化，其进而改变共价连接的氧化还原标签与询问电极交换电子的效率。然而，适体选择策略通常不选择构象转换架构，因此迄今为止已经报道了几种方法，通过这些方法可以重新改造适体，使得它们经历支持有效E-AB信号传导所需的结合诱导的转换。在这里，我们系统地比较了这些再工程方法的优点，使用具有代表性的小分子腺苷三磷酸和蛋白质人免疫球蛋白E的特异性适体。我们发现，虽然许多适体架构支持E-AB信号传导，但在我们研究的各种构建体中，观察到的信号增益（靶结合后信号的相对变化）变化超过两个数量级（例如，对于我们的ATP传感器，范围从-10%到200%）。因此，开关结构的优化是实现最大E-AB信号增益的重要因素，并且我们发现这种最佳几何结构特定于构建传感器的适体序列。
Electrochemical aptamer-based (E-AB) sensors have emerged as a promising and versatile new biosensor platform. Combining the generality and specificity of aptamer–ligand interactions with the selectivity and convenience of electrochemical readouts, this approach affords the detection of a wide variety of targets directly in complex, contaminant-ridden samples, such as whole blood, foodstuffs and crude soil extracts, without the need for exogenous reagents or washing steps. Signaling in this class of sensors is predicated on target-induced changes in the conformation of an electrode-bound probe aptamer that, in turn, changes the efficiency with which a covalently attached redox tag exchanges electrons with the interrogating electrode. Aptamer selection strategies, however, typically do not select for the conformation-switching architectures, and as such several approaches have been reported to date by which aptamers can be re-engineered such that they undergo the binding-induced switching required to support efficient E-AB signaling. Here, we systematically compare the merits of these re-engineering approaches using representative aptamers specific to the small molecule adenosine triphosphate and the protein human immunoglobulin E. We find that, while many aptamer architectures support E-AB signaling, the observed signal gain (relative change in signal upon target binding) varies by more than two orders of magnitude across the various constructs we have investigated (e.g., ranging from −10% to 200% for our ATP sensors). Optimization of the switching architecture is thus an important element in achieving maximum E-AB signal gain and we find that this optimal geometry is specific to the aptamer sequence upon which the sensor is built.
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影响因子：
16.6
作者：
Xiao, Y;Lubin, AA;Plaxco, KW
通讯作者：
Plaxco, KW
影响因子：
--
作者：
Lin, CH;Patel, DJ
通讯作者：
Patel, DJ
影响因子：
15
作者：
Nutiu, R;Li, YF
通讯作者：
Li, YF
影响因子：
15
作者：
Radi, AE;Sánchez, JLA;O'Sullivan, CK
通讯作者：
O'Sullivan, CK
影响因子：
64.8
作者：
ELLINGTON, AD;SZOSTAK, JW
通讯作者：
SZOSTAK, JW