A hairpin DNA aptamer coupled with groove binders as a smart switch for a field-effect transistor biosensor
A hairpin DNA aptamer coupled with groove binders as a smart switch for a field-effect transistor biosensor
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DOI：
10.1016/j.bios.2011.12.022
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发表时间：
2012-02-15
影响因子：
12.6
通讯作者：
Miyahara, Yuji
中科院分区：
文献类型：
--
作者：
Goda, Tatsuro;Miyahara, Yuji
我们在这里报道了一种具有抗ATP适体序列的发夹结构DNA，通过在作为场效应晶体管（FET）扩展栅极的金电极表面的纳米级分子内位移，成功地以温度依赖的方式检测到目标ATP或腺苷。发夹适体的结构从闭环到开环的转换伴随着预载DNA结合剂（DAPI）从发夹适体的茎部释放到溶液阶段。由于靶捕获，DAPI（2+）从栅极/溶液纳米界面的扩散层中丢失了固有正电荷，这是场效应产生特定信号的原因。我们强调了结构DNA适体与FET结合的一个新方面：负载dapi的发夹适体甚至成功地检测了未带电的腺苷，这仍然是基于FET的生物传感器的主要挑战。由于寡核苷酸适配体的一级和二级结构设计简单，因此很容易将该技术应用于各种生物分析物，而不考虑其电荷。鉴于这些优势，我们的发现可能为设计基于半导体的生物传感器的刺激响应“智能”生物分子开关提供新的趋势。(C) 2011 Elsevier B.V.版权所有
We report here that a hairpin-structured DNA that possesses an anti-ATP aptamer sequence successfully detected target ATP or adenosine in a temperature-dependent manner by nanoscale intramolecular displacement on the surface of a gold electrode as an extended gate of a field-effect transistor (FET). The structural switching of the hairpin aptamer from closed loop to open-loop conformations was accompanied by the release of the preloaded DNA binder (DAPI) from the stem part of the hairpin aptamer into the solution phase. The loss of intrinsic positive charges of DAPI (2+) from the diffusion layer at the gate/solution nano-interface as a result of target capturing was responsible for generating a specific signal by the field-effect. We emphasize a new aspect of the structured DNA aptamer in combination with FET: the DAPI-loaded hairpin aptamer successfully detected even uncharged adenosine, which remains a major challenge for FET-based biosensors. Given the simplicity in design of the primary and secondary structures of oligonucleotide aptamers, it is easy to apply this technology to a wide variety of bio-analytes, irrespective of their electric charges. In view of these advantages, our findings may offer a new trend in the design of stimuli-responsive "smart" biomolecular switches for semiconductor-based biosensors. (C) 2011 Elsevier B.V. All rights reserved.