School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, 225002, PR China.
Department of Chemical Engineering, Yangzhou Polytechnic Institute, Yangzhou, 225127, PR China.
Biosens Bioelectron. 2021 Jul 15;184:113229. doi: 10.1016/j.bios.2021.113229. Epub 2021 Apr 7.
It is very important to develop a rapid, simple, low cost point-of-care (POC) method for the early diagnosis of pathogens. In this work, a flexible paper-based electrode based on nickel metal-organic framework (Ni-MOF) composite/Au nanoparticles/carbon nanotubes/polyvinyl alcohol (Ni-Au composite/CNT/PVA) was constructed to detect target human immunodeficiency virus (HIV) DNA by DNA hybridization using methylene blue (MB) as a redox indicator. The CNT/PVA and Ni-Au composite were deposited on the cellulose membrane by vacuum filtration and drop-coating method in turn to obtain Ni-Au composite/CNT/PVA (CCP) film electrode. Compared to the CNT/PVA film electrode, CCP film electrode makes a higher loading of the probe DNA for its large specific surface area and conjugated π-electron system that can provide hydrogen bond sources to achieve interactions between MOF and single-stranded DNA, which improves the sensitivity for detecting target DNA. The variation of peak current for MB molecules adsorbed onto DNA before and after hybridization with HIV DNA was monitored. Electrochemical results proved that the CCP film maintained stable electrochemical property even after bending 200 times or stretching under different strains from 0% to 20%. The flexible paper electrode showed excellent sensing performance with a linear range of 10 nM-1 μM and a low detection limit of 0.13 nM. The target HIV DNA was successfully detected even in complex serum samples using the flexible CCP film electrode. Therefore, the simple and inexpensive flexible paper-based MOF composite film electrode can also be utilized for other pathogens POC diagnosis.
开发一种快速、简单、低成本的即时诊断（POC）方法对于病原体的早期诊断非常重要。在这项工作中，构建了一种基于镍金属有机骨架（Ni-MOF）复合材料/Au 纳米粒子/碳纳米管/聚乙烯醇（Ni-Au 复合材料/CNT/PVA）的柔性纸质电极，通过亚甲基蓝（MB）作为氧化还原指示剂，用于通过 DNA 杂交检测目标人免疫缺陷病毒（HIV）DNA。通过真空过滤和滴涂法依次将 CNT/PVA 和 Ni-Au 复合材料沉积在纤维素膜上，以获得 Ni-Au 复合材料/CNT/PVA（CCP）薄膜电极。与 CNT/PVA 薄膜电极相比，CCP 薄膜电极具有更大的比表面积和共轭π电子体系，为 MOF 与单链 DNA 之间的相互作用提供了氢键源，从而提高了检测目标 DNA 的灵敏度，因此可以负载更多的探针 DNA。监测了与 HIV DNA 杂交前后吸附在 DNA 上的 MB 分子的峰电流变化。电化学结果证明，即使在弯曲 200 次或在 0%至 20%的不同应变下拉伸后，CCP 薄膜仍保持稳定的电化学性能。该柔性纸电极具有出色的传感性能，线性范围为 10 nM-1 μM，检测限低至 0.13 nM。即使在复杂的血清样本中，也成功地使用柔性 CCP 薄膜电极检测到了目标 HIV DNA。因此，这种简单且经济的柔性基于 MOF 复合薄膜电极也可以用于其他病原体 POC 诊断。
