High Surface Area Electrodes Generated via Electrochemical Roughening Improve the Signaling of Electrochemical Aptamer-Based Biosensors
High Surface Area Electrodes Generated via Electrochemical Roughening Improve the Signaling of Electrochemical Aptamer-Based Biosensors
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DOI：
10.1021/acs.analchem.7b02830
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发表时间：
2017-11-21
影响因子：
7.4
通讯作者：
Plaxco, Kevin W.
中科院分区：
文献类型：
--
作者：
Arroyo-Curras, Netzahualcoyotl;Scida, Karen;Plaxco, Kevin W.
基于电化学适配体 (E-AB) 的传感器平台提供了一种模块化方法，可对活体内的特定分子目标（无论其化学反应性如何）进行连续、实时测量。然而，要实现这一目标，需要制造足够小的传感器以插入静脉，对于我们采用的大鼠动物模型，需要直径小于 200 μm 的设备。当这些小型设备部署在体内复杂、波动的环境中时，其有限的表面积反过来会导致法拉第电流低和信噪比差。为此，我们开发了一种电化学粗糙化方法，通过增加金电极的微观表面积来增强小型电化学传感器的信号传输，在这种情况下允许更多的氧化还原报告修饰的适体堆积在表面上，从而显着提高信噪比。与以前实现微观粗糙金表面的方法不同，我们的方法在 5 分钟蚀刻过程中采用计时电流脉冲，易于与批量生产兼容。使用这些高表面积电极，我们展示了 E-AB 传感器测量活体大鼠完整药物药代动力学特征的能力，在确定药物处置参数时精度优于 10%。
The electrochemical, aptamer-based (E-AB) sensor platform provides a modular approach to the continuous, real-time measurement of specific molecular targets (irrespective of their chemical reactivity) in situ in the living body. To achieve this, however, requires the fabrication of sensors small enough to insert into a vein, which, for the rat animal model we employ, entails devices less than 200 mu m in diameter. The limited surface area of these small devices leads, in turn, to low faradaic currents and poor signal-to-noise ratios when deployed in the complex, fluctuating environments found in vivo. In response we have developed an electrochemical roughening approach that enhances the signaling of small electrochemical sensors by increasing the microscopic surface area of gold electrodes, allowing in this case more redox-reporter-modified aptamers to be packed onto the surface, thus producing significantly improved signal-to-noise ratios. Unlike previous approaches to achieving microscopically rough gold surfaces, our method employs chronoamperometric pulsing in a 5 min etching process easily compatible with batch manufacturing. Using these high surface area electrodes, we demonstrate the ability of E-AB sensors to measure complete drug pharmacokinetic profiles in live rats with precision of better than 10% in the determination of drug disposition parameters.