Key Laboratory of Optic-Electric Sensing and Analytical Chemistry for Life Science, Shandong Key Laboratory of Biochemical Analysis, Key Laboratory of Analytical Chemistry for Life Science in Universities of Shandong, Key Laboratory of Eco-Chemical Engineering, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China.
ACS Appl Mater Interfaces. 2024 Oct 30;16(43):59648-59661. doi: 10.1021/acsami.4c16975. Epub 2024 Oct 15.
This study investigates three metal-organic frameworks (MOFs) with distinct Brunauer-Emmett-Teller (BET) surface areas and pore sizes: MOF (1274 m/g, <0.7 nm), MOF (371 m/g, 1.5 nm), and MOF (1917 m/g, 2 nm). Methylene blue (MB, 1.4 × 0.7 × 0.2 nm) and triferrocene (tri-FC, 1.2 × 0.9 × 0.3 nm) were adsorbed onto these MOFs. Specific DNA segments targeting SARS-CoV-2 (P and P) were employed to block the pores of the MOFs, leading to the formation of DNA-gated MOFs: MOF/MB/ and MOF/tri-FC/P. These constructs were subsequently integrated with four-arm poly(ethylene glycol) amine (4-arm-PEG-NH)-modified gold electrodes to create the corresponding sensors (MOF/MB/P+MOF/tri-FC/P@4-arm-PEG-NH@Au NPs@GCE). The DNA-gated MOF system exhibited the highest loading capacity and a 3-fold increase in sensing efficiency following the introduction of SARS-CoV-2 target DNA, surpassing the performance of the other systems. This study highlights the enhancement of the DNA-gated MOFs when the three-dimensional structures of the guest molecules closely align with the pore sizes of the MOFs. It emphasizes a critical aspect of the traditional design approach for electrochemical sensors based on MOF encapsulation, which often prioritizes BET surface areas while neglecting the compatibility between the sizes of guest molecules and MOF pore diameters. Moreover, the sensor effectively discriminated between SARS-CoV-2 and SARS-CoV by precisely aligning the SARS-CoV-2 target DNA with P and P. In contrast, the specific genetic targets (S) from SARS-CoV showed complete mismatches with P and a three-base deviation with P. This differentiation was achieved in a simple one-step assay, even in 5% serum, across a linear concentration range of 10 to 10 M. This range signifies an expansion of 2 to 3 orders of magnitude compared to sensors that inaccurately selected MOFs.
本研究考察了三种具有不同比表面积和孔径的金属有机骨架（MOFs）：MOF（1274 m/g，<0.7 nm）、MOF（371 m/g，1.5 nm）和 MOF（1917 m/g，2 nm）。亚甲基蓝（MB，1.4×0.7×0.2 nm）和三茂铁（tri-FC，1.2×0.9×0.3 nm）被吸附到这些 MOFs 上。针对 SARS-CoV-2 的特定 DNA 片段被用来阻塞 MOFs 的孔，形成 DNA 门控 MOFs：MOF/MB/ 和 MOF/tri-FC/P。这些构建体随后与四臂聚乙二醇胺（4-arm-PEG-NH）修饰的金电极集成，以创建相应的传感器（MOF/MB/P+MOF/tri-FC/P@4-arm-PEG-NH@Au NPs@GCE）。在引入 SARS-CoV-2 靶 DNA 后，DNA 门控 MOF 系统表现出最高的负载能力和 3 倍的传感效率，超过了其他系统的性能。本研究强调了当客体分子的三维结构与 MOFs 的孔径紧密匹配时，DNA 门控 MOFs 的增强作用。它强调了基于 MOF 封装的电化学传感器的传统设计方法的一个关键方面，该方法通常优先考虑 BET 比表面积，而忽略了客体分子的大小与 MOF 孔径之间的兼容性。此外，该传感器通过将 SARS-CoV-2 的靶 DNA 与 P 和 P 精确对齐，有效地区分了 SARS-CoV-2 和 SARS-CoV。相比之下，SARS-CoV 的特定遗传靶标（S）与 P 和 P 完全不匹配，与 P 有三个碱基的偏差。这种区分是在一个简单的一步检测中实现的，甚至在 5%的血清中，在 10 到 10 M 的线性浓度范围内。与不准确选择 MOFs 的传感器相比，这个范围扩大了 2 到 3 个数量级。
