School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China.
School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China.
Talanta. 2022 Oct 1;248:123619. doi: 10.1016/j.talanta.2022.123619. Epub 2022 May 27.
Biological nanopore-based single-molecule detection technology has shown ultrahigh sensitivity to various target analyte. But the detection scope of interesting targets is limited due to the lack of effective signal conversion strategies. In addition, conventional nanopore detection instruments are cumbersome, resulting nanopore detection can only be performed in laboratory. Herein, a customizable nanopore current amplifier is constructed to lower the cost and increase the portability of the nanopore instrument, and then an immobilized aptamer-based signal conversion strategy is proposed for α-hemolysin (α-HL) nanopore to detect small molecules (ochratoxin A, OTA). The presence of OTA in sample would trigger the release of probe single-strand DNA (ssDNA) from magnetic beads, which could subsequently cause current blockage in nanopore. The results show that the signal frequency of probe ssDNA has a linear relationship with the OTA concentration in the range of 2 × 10～2 × 10 pmol/L. Compared to other methods, our sensing system has achieved an ultra-sensitive detection of OTA with the detection limit as low as 1.697 pmol/L. This strategy could broaden the scope of nanopore detection and have the potential for rapid and in-situ detection of other food contaminants in the future.
基于生物纳米孔的单分子检测技术对各种目标分析物表现出超高的灵敏度。但由于缺乏有效的信号转换策略，感兴趣目标的检测范围有限。此外，传统的纳米孔检测仪器繁琐，导致纳米孔检测只能在实验室进行。在此，构建了一种可定制的纳米孔电流放大器，以降低纳米孔仪器的成本并提高其便携性，然后提出了一种基于固定化适体的信号转换策略，用于 α-溶血素（α-HL）纳米孔检测小分子（赭曲霉毒素 A，OTA）。样品中 OTA 的存在会触发探针单链 DNA（ssDNA）从磁珠上释放，从而导致纳米孔中的电流阻塞。结果表明，探针 ssDNA 的信号频率与 OTA 在 2×10～2×10 pmol/L 范围内的浓度呈线性关系。与其他方法相比，我们的传感系统对 OTA 的检测具有超灵敏的检测能力，检测限低至 1.697 pmol/L。该策略可以拓宽纳米孔检测的范围，并有望在未来用于快速和原位检测其他食品污染物。
