Functionalized nanogaps embedded in nanopores show a strong potential for enhancing the detection of biomolecules, their length, type, and sequence. This detection is strongly dependent on the features of the target biomolecules, as well as the characteristics of the sensing device. In this work, through quantum‐mechanical calculations, we elaborate on representative such aspects for the specific case of DNA detection and read‐out. These aspects include the influence of single DNA nucleotide rotation within the nanogap and the current‐voltage (I‐V) characteristics of the nanogap. The results unveil a distinct variation in the electronic current across the functionalized device for the four natural DNA nucleotides with the applied voltage. These also underline the asymmetric response of the rotating nucleotides on this applied voltage and the respective variation in the rectification ratio of the device. The electronic tunneling current across the nanogap can be further enhanced through the proper choice of an applied bias voltage. We were able to correlate the enhancement of this current to the nucleotide rotation dynamics and a shift of the electronic transmission peaks towards the Fermi level. This nucleotide specific shift further reveals the sensitivity of the device in reading‐out the identity of the DNA nucleotides for all different configurations in the nanogap. We underline the important information that can be obtained from both the I‐V curves and the rectification characteristics of the nanogap device in view of accurately reading‐out the DNA information. We show that tuning the applied bias can enhance this detection and discuss the implications in view of novel functionalized nanopore sequencers.

中文翻译：

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用于 DNA 读出的功能化纳米间隙：核苷酸旋转和电流-电压曲线。

嵌入纳米孔中的功能化纳米间隙显示出增强生物分子及其长度、类型和序列检测的强大潜力。这种检测强烈依赖于目标生物分子的特征，以及传感装置的特性。在这项工作中，通过量子力学计算，我们详细阐述了 DNA 检测和读出的特定情况下具有代表性的这些方面。这些方面包括纳米间隙内单个 DNA 核苷酸旋转的影响和纳米间隙的电流-电压 (I-V) 特性。结果揭示了在施加电压的情况下，四种天然 DNA 核苷酸的功能化装置上的电子电流存在明显变化。这些也强调了旋转核苷酸对该施加电压的不对称响应以及器件整流比的相应变化。The electronic tunneling current across the nanogap can be further enhanced through the proper choice of an applied bias voltage. 我们能够将这种电流的增强与核苷酸旋转动力学和电子传输峰向费米能级的移动联系起来。这种核苷酸特异性转变进一步揭示了该设备在读取纳米间隙中所有不同配置的 DNA 核苷酸身份时的敏感性。为了准确读取 DNA 信息，我们强调了可以从 I-V 曲线和纳米间隙器件的整流特性中获得的重要信息。