Harnessing the affinity of magnetic nanoparticles toward dye-labeled DNA and developing it as an universal aptasensor revealed by lipopolysaccharide detection
Harnessing the affinity of magnetic nanoparticles toward dye-labeled DNA and developing it as an universal aptasensor revealed by lipopolysaccharide detection
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利用磁性纳米颗粒对染料标记 DNA 的亲和力，并将其开发为通过脂多糖检测揭示的通用适体传感器
DOI：
10.1016/j.aca.2018.06.060
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发表时间：
2018
影响因子：
6.2
通讯作者：
Diao Aipo
中科院分区：
文献类型：
--
作者：
Ma Long;Sun Nana;Meng Yuanyuan;Tu Chunhao;Cao Xiuqi;Wei Yongchang;Chu Liqiang;Diao Aipo
在目前的研究中，我们发现几种磁性纳米颗粒(MNPs)能够吸附DNA分子，表面工程将有助于调节这种相互作用。然后我们重点研究了聚乙烯亚胺(PEI)包覆的MNPs(PEI-MNPs)与单链DNA(单链DNA)的组装，发现这种组装是由两种力介导的，即MNPs表面电荷与DNA磷酸盐骨架的静电相互作用以及MNPs外部铁离子(特别是Fe3+)与DNA磷酸盐骨架的配位作用。染料标记的DNA与PEI-MNPs络合后，荧光被显著猝灭，这是由静电猝灭引起的。这种PEI-MNPs与DNA相互作用，可用于设计一种新型的适体传感器。这一点以选择性和灵敏的内毒素检测为例。方法的检出限为∼35 ng/m L，线性范围为50-10 g/m L。与广泛使用的氧化石墨烯(GO)-单链DNA适体传感器相比，我们还证明了基于PEI-MNPs的传感器能够更好地避免干扰蛋白质导致的非特异性DNA置换，产生更令人满意的信本比。我们提出的传感器可以作为经典Go-DNA传感器的补充。综上所述，我们的工作提供了对MNPs-DNA相互作用的基本理解，也为开发基于MNPs的新型传感方法铺平了道路，这将有助于纳米生物界面和DNA辅助生物分析、DNA配位纳米材料和DNA定向组装。
In current study, we have found that several magnetic nanoparticles (MNPs) are able to absorb DNA molecules, and surface engineering would be beneficial to tune such interaction. We then have focused on the assembly of polyethylenimine (PEI) coated MNPs (PEI-MNPs) with ssDNA (single-stranded DNA) and found this assembly is mediated by two forces, namely the electrostatic interactions of surface charges of MNPs and the phosphate backbones of DNA; as well as the coordination of exterior iron ions (especially Fe3+) of MNPs and DNA phosphate backbones. The fluorescence of dye-labeled DNA is significantly quenched when being complexed with PEI-MNPs, which is proved to be caused by static quenching. This PEI-MNPs interact with DNA, which could be harnessed for devising a novel type of aptasensor. This has been examplified by the selective and sensitive detection of lipopolysaccharide (LPS). The LOD (limit of detection) is ∼35 ng/mL and the linear range from 50 ng/mL to 10 μg/mL. Compared with widely used graphene oxide (GO)‒ssDNA aptamer sensors, we also have demonstrated that the PEI-MNPs based sensor is able to better avoid non-specific DNA displacement by interfering proteins, generating more satisfactory signal-to-background ratio. Our proposed sensor could be a supplement to classic GO‒DNA sensors. In summary, our work provides fundamental understanding of MNPs‒DNA interactions and also paves the way for developing novel MNPs based sensing approaches, which would contribute to nano‒bio interface and DNA-assisted bio-analysis, DNA-coordinated nano-materials and DNA-directed assembly.