College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210039, China.
Int J Mol Sci. 2019 Feb 10;20(3):741. doi: 10.3390/ijms20030741.
The prion protein (PrP) has drawn widespread attention due to its pathological potential to cause prion diseases. Herein, we successfully synthesized Fe₃C@C by carbonizing Fe₃O₄-lignin clusters, which were prepared through a facile hydrogen bonding interaction between ≡Fe-OH and hydroxyl groups of lignin. Our in-depth investigation confirmed that the composites were Fe₃C@C core/shell particles. We constructed a novel sandwich surface plasmon resonance (SPR) detection assay for sensitive PrP detection, utilizing bare gold surface and aptamer-modified Fe₃C@C (Fe₃C@C-aptamer). Due to the highly specific affinity of Fe₃C@C-aptamer towards PrP, the sandwich type SPR sensor exhibited excellent analytical performance towards the discrimination and quantitation of PrP. A good linear relationship was obtained between the SPR responses and the logarithm of PrP concentrations over a range of 0.1⁻200 ng/mL. The detection sensitivity for PrP was improved by ~10 fold compared with the SPR direct detection format. The required detection time was only 20 min. The specificity of the present biosensor was also confirmed by PrP and other reagents as controls. This proposed approach could also be used to isolate and detect other highly pathogenic biomolecules with similar structural characteristics by altering the corresponding aptamer in the Fe₃C@C conjugates.
朊病毒蛋白（PrP）因其潜在的病理性，能够导致朊病毒疾病，因此受到了广泛关注。在此，我们成功地通过碳化 Fe₃O₄-木质素簇来合成 Fe₃C@C，该过程是通过 ≡Fe-OH 与木质素中的羟基之间的氢键相互作用来实现的。我们的深入研究证实，这些复合材料是 Fe₃C@C 核/壳粒子。我们构建了一种新颖的三明治表面等离子体共振（SPR）检测方法，用于灵敏检测 PrP，利用裸金表面和适配体修饰的 Fe₃C@C（Fe₃C@C-适配体）。由于 Fe₃C@C-适配体对 PrP 具有高度特异性的亲和力，这种三明治型 SPR 传感器对 PrP 的鉴别和定量表现出优异的分析性能。在 0.1⁻200 ng/mL 的范围内，SPR 响应与 PrP 浓度的对数之间呈现出良好的线性关系。与 SPR 直接检测模式相比，PrP 的检测灵敏度提高了约 10 倍。该生物传感器的特异性也通过 PrP 和其他试剂作为对照得到了证实。通过改变 Fe₃C@C 缀合物中的相应适配体，这种方法还可以用于分离和检测具有相似结构特征的其他高致病性生物分子。
