Biosensors based on field-effect devices (bioFETs) offer numerous advantages over current technologies and therefore have attracted immense research over the decades. However, short Debye screening length in highly ionic physiological solutions remains the main obstacle for bioFET realization. This challenge becomes considerably more acute at the electrolyte-oxide interface of the sensing area due to high ion concentration induced by the charged amphoteric sites, which prohibits any attempt to employ the field-effect mechanism to "sense" any charged biomolecules. In this work, we present an electrostatic approach by which the double layer (DL) excess ion concentration is removed, thus forcing the DL ion concentration to match the bulk concentration, which subsequently forces bulk screening length at the DL, thereby "exposing" target biomolecules to the underlying bioFET. To this end, we employ local tunable surface electric fields, introduced to the DL using surface passivated-metal electrodes. We examine numerically and analytically the effect of these electric fields on the DL ion distribution. We also numerically demonstrate the feasibility of the proposed approach for a fully depleted silicon-on-insulator based bioFET and show how the threshold voltage shift induced by the presence of target molecules increases by almost two orders of magnitude upon the removal of the surface excess ion population.

中文翻译：

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用于生物传感应用的溶液-固相界面上的静电控制德拜屏蔽长度。

基于场效应器件（bioFET）的生物传感器提供了超过当前技术的众多优势，因此在过去的几十年中吸引了众多研究。然而，在高离子生理溶液中较短的德拜筛选长度仍然是bioFET实现的主要障碍。由于带电的两性位点引起的高离子浓度，该挑战在传感区域的电解质-氧化物界面处变得更加严重，这阻止了任何尝试使用场效应机制“感知”任何带电生物分子的尝试。在这项工作中，我们提出了一种静电消除方法，通过该方法可以去除双层（DL）多余的离子浓度，从而迫使DL离子浓度与体积浓度匹配，从而迫使DL处的体积筛选长度，从而“暴露” 将生物分子靶向到潜在的bioFET。为此，我们采用局部可调谐表面电场，该表面电场是使用表面钝化金属电极引入DL的。我们在数值和分析上检查了这些电场对DL离子分布的影响。我们还以数值方式证明了该方法对于完全耗尽绝缘体上硅的bioFET的可行性，并显示了在去除表面多余离子后，由目标分子的存在引起的阈值电压偏移如何增加近两个数量级。人口。我们在数值和分析上检查了这些电场对DL离子分布的影响。我们还以数值方式证明了该方法对于完全耗尽绝缘体上硅的bioFET的可行性，并显示了在去除表面多余离子后，由目标分子的存在引起的阈值电压偏移如何增加近两个数量级。人口。我们在数值和分析上检查了这些电场对DL离子分布的影响。我们还以数值方式证明了该方法对于完全耗尽绝缘体上硅的bioFET的可行性，并显示了在去除表面多余离子后，由目标分子的存在引起的阈值电压偏移如何增加近两个数量级。人口。