Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, Institute for Clean Energy and Advanced Materials, Faculty of Materials and Energy, Southwest University, Chongqing, 400715, PR China.
Britton Chance Center for Biomedical Photonics at Wuhan National Laboratory for Optoelectronics-Hubei Bioinformatics & Molecular Imaging Key Laboratory, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, PR China.
Biosens Bioelectron. 2020 Mar 15;152:112011. doi: 10.1016/j.bios.2020.112011. Epub 2020 Jan 8.
For ionic current rectification (ICR) based sensing, nanopore functionalizations are mostly designed for directly binding target molecules to generate detectable signals from surface charge variation. However, this strategy is highly dependent on the charge difference between the captured molecules and surface functionalization layers, which will increase the nanopore design difficulty and subsequently limit the nanopore applicability. Another key challenge for ICR based sensing is the nanopore regenerability that is critical if online monitoring or repeated determination needs to be performed with one sensor. Though some types of nanopore regeneration have been realized on some specific targets or with harsh conditions, it is still highly favored to develop a regenerability using mild conditions for various targets. To address these two challenges, we developed a novel and universal sensing strategy for aptamer-functionalized nanopore that can be easily regenerated after each usage without any harsh conditions and independent of target molecule charge or size for ICR based nanopore sensing. Ochratoxin A (OTA) was used as a model analyte and its corresponding aptamer partially hybridized with the pre-immobilized complementary DNA (cDNA) onto the nanopore inner surface. We demonstrated that the recognition and conjugation of OTA with its aptamer resulted in rectified ionic current variations due to the dissociation between the OTA aptamer and its partially paired cDNA. The performance of this nanopore sensor including sensitivity, selectivity, regenerability, and applicability was characterized using rectified ionic current. This nanopore sensing strategy will provide a promising platform for extensive targets and online sensing applications.
对于基于离子电流整流（ICR）的传感，纳米孔功能化大多设计用于直接结合靶分子，以从表面电荷变化产生可检测的信号。然而，这种策略高度依赖于捕获分子和表面功能化层之间的电荷差异，这将增加纳米孔设计的难度，并随后限制纳米孔的适用性。基于 ICR 的传感的另一个关键挑战是纳米孔的可再生性，如果需要在线监测或用一个传感器进行重复测定，则这一点至关重要。虽然已经在一些特定的靶标或苛刻的条件下实现了一些类型的纳米孔再生，但仍然强烈希望开发一种在各种靶标下使用温和条件的再生能力。为了解决这两个挑战，我们开发了一种用于适体功能化纳米孔的新型通用传感策略，该策略可以在不使用任何苛刻条件的情况下，在每次使用后轻松再生，并且与靶标分子的电荷或大小无关，适用于基于 ICR 的纳米孔传感。赭曲霉毒素 A（OTA）被用作模型分析物，其相应的适体与预先固定在纳米孔内表面的互补 DNA（cDNA）部分杂交。我们证明，由于 OTA 适体与其部分配对 cDNA 之间的解离，OTA 与其适体的识别和缀合导致了整流离子电流的变化。使用整流离子电流对这种纳米孔传感器的性能，包括灵敏度、选择性、可再生性和适用性进行了表征。这种纳米孔传感策略将为广泛的靶标和在线传感应用提供一个有前途的平台。
