Electroactivity of Aptamer at Soft Microinterface Arrays
Electroactivity of Aptamer at Soft Microinterface Arrays
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DOI：
10.1021/acs.analchem.8b01172
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发表时间：
2018-07-17
影响因子：
7.4
通讯作者：
Arrigan, Damien W. M.
中科院分区：
文献类型：
--
作者：
Felisilda, Bren Mark B.;Arrigan, Damien W. M.
研究了凝血酶结合适体（TBA，15-mer）在有机凝胶微界面阵列上的电化学行为。当两个相中仅存在背景电解质时，TBA未显示任何响应。在文献报道表面活性剂会影响核酸检测的基础上，研究了在十六烷基三甲基铵（CTA+）存在下的响应。当TBA和CTA（+）都在水相中时，CTA（+）的转移电流减小，表明CTA（+）与TBA相互作用。将CTA（+）掺入有机相中的实验显示了尖锐的电流峰，与CTA（+）-TBA复合物的界面形成一致。然而，使用CTA（+）作为有机相电解质阳离子，作为与四（4-氯苯基）硼酸盐的盐，大大改善了对TBA的响应。在这种情况下，一个独特的峰值响应（在约。-0.25V）归因于CTA（+）穿过软界面与水相TBA络合。采用该方法作为检测步骤使得检测限为0.11 M TBA（通过循环伏安法）。此外，在生理浓度的镁离子的存在下，由于镁离子诱导的折叠TBA的TBA响应的消失。此外，TBA的电流响应通过添加凝血酶而降低，表明TBA与该结合伴侣相互作用。最后，界面的表面活性剂-适体的相互作用进行了探讨，在合成的尿液基质，提供了0.29 μ M TBA的检测限。这些结果表明，适体结合的相互作用，可以通过电化学监测在水-有机界面，并开辟了一个新的可能性，在适体结合检测。
The electrochemical behavior of a synthetic oligonucleotide, thrombin-binding aptamer (TBA, 15-mer), was explored at a liquid-organogel microinterface array. TBA did not display any response when only background electrolytes were present in both phases. On the basis of literature reports that surfactants can influence nucleic acid detection, the response in the presence of cetyltrime-thylammonium (CTA+) was examined. With both TBA and CTA(+) in the aqueous phase, the transfer current for CTA(+) was diminished, signifying the interaction of CTA(+) with TBA. Experiments with CTA(+) spiked into the organic phase revealed a sharp current peak, consistent with the interfacial formation of a CTA(+)-TBA complex. However, use of CTA(+) as the organic phase electrolyte cation, as the salt with tetrakis(4-chlorophenyOborate, greatly improved the response to TBA. In this case, a distinctive peak response (at ca. -0.25 V) was attributed to the transfer of CTA(+) across the soft interface to complex with aqueous phase TBA. Employing this process as a detection step enabled a detection limit of 0.11 M TBA (by cyclic voltammetry). Furthermore, the presence of magnesium cations at physiological concentration resulted in the disappearance of the TBA response because of Mg2+-induced folding of TBA. Also, the current response of TBA was decreased by the addition of thrombin, indicating TBA interacted with this binding partner. Finally, the interfacial surfactant-aptamer interaction was explored in a synthetic urine matrix that afforded a detection limit of 0.29 mu M TBA. These results suggest that aptamer-binding interactions can be monitored by electrochemistry at aqueous-organic interfaces and open up a new possibility for detection in aptamer-binding assays.