Mussi Valentina, Ledda Mario, Convertino Annalisa, Lisi Antonella
Institute for Microelectronics and Microsystems, National Research Council, IMM-CNR, 00133 Rome, Italy.
Institute of Translational Pharmacology, National Research Council, IFT-CNR, 00133 Rome, Italy.
Micromachines (Basel). 2021 Mar 4;12(3):264. doi: 10.3390/mi12030264.
This article demonstrates the possibility to use a novel powerful approach based on Raman mapping of analyte solutions drop casted on a disordered array of Ag covered silicon nanowires (Ag/SiNWs), to identify the characteristic spectral signal of the four DNA bases, adenine (A), thymine (T), cytosine (C), and guanine (G), at concentration as low as 10 ng/µL, and to study their specific way of interacting with the nanostructured substrate. The results show a distinctive and amplified interaction of guanine, the base that is most susceptible to oxidation, with the nanostructured surface. Our findings explain the recently revealed diverse behaviour of cancer and normal DNA deposited on the same Ag/SiNWs, which is ascribed to mechanical deformation and base lesions present on the oxidised DNA molecule backbone and causes detectable variation in the Raman signal, usable for diagnostic purposes. The notable bio-analytical capability of the presented platform, and its sensitivity to the molecule mechanical conformation at the single-base level, thus provides a new reliable, rapid, label-free DNA diagnostic methodology alternative to more sophisticated and expensive sequencing ones.
本文展示了一种基于拉曼映射的新的强大方法的可能性，该方法用于分析滴铸在无序排列的银覆盖硅纳米线（Ag/SiNWs）上的分析物溶液，以识别四种DNA碱基，即腺嘌呤（A）、胸腺嘧啶（T）、胞嘧啶（C）和鸟嘌呤（G）在低至10 ng/µL浓度下的特征光谱信号，并研究它们与纳米结构底物相互作用的特定方式。结果表明，最易氧化的碱基鸟嘌呤与纳米结构表面存在独特且增强的相互作用。我们的发现解释了最近揭示的沉积在相同Ag/SiNWs上的癌症DNA和正常DNA的不同行为，这归因于氧化DNA分子主链上存在的机械变形和碱基损伤，并导致拉曼信号出现可检测的变化，可用于诊断目的。所展示平台显著的生物分析能力及其对单碱基水平分子机械构象的敏感性，从而提供了一种新的可靠、快速、无标记的DNA诊断方法，可替代更复杂且昂贵的测序方法。
