Innovative Molecular Materials Group, School of Chemistry & Chemical Engineering, Queen's University, Belfast BT9 5AG, UK.
Chemistry. 2012 Apr 23;18(17):5394-400. doi: 10.1002/chem.201103520. Epub 2012 Mar 20.
Unlabelled single- and double-stranded DNA (ssDNA and dsDNA, respectively) has been detected at concentrations ≥10(-9) M by surface-enhanced Raman spectroscopy. Under appropriate conditions the sequences spontaneously adsorbed to the surface of both Ag and Au colloids through their nucleobases; this allowed highly reproducible spectra with good signal-to-noise ratios to be recorded on completely unmodified samples. This eliminated the need to promote absorption by introducing external linkers, such as thiols. The spectra of model ssDNA sequences contained bands of all the bases present and showed systematic changes when the overall base composition was altered. Initial tests also showed that small but reproducible changes could be detected between oligonucleotides with the same bases arranged in a different order. The spectra of five ssDNA sequences that correspond to different strains of the Escherichia coli bacterium were found to be sufficiently composition-dependent so that they could be differentiated without the need for any advanced multivariate data analysis techniques.
未标记的单链和双链 DNA（分别为 ssDNA 和 dsDNA）的浓度≥10（-9）M 时可通过表面增强拉曼光谱检测到。在适当的条件下，序列通过其核碱基自发吸附到 Ag 和 Au 胶体的表面；这使得能够在完全未修饰的样品上记录具有良好信噪比的高度可重现的光谱。这消除了通过引入外部接头（例如硫醇）来促进吸收的需要。模型 ssDNA 序列的光谱包含所有存在碱基的谱带，并且当整体碱基组成改变时显示出系统变化。初步测试还表明，即使碱基相同但排列顺序不同的寡核苷酸之间也可以检测到微小但可重复的变化。对应于不同大肠杆菌菌株的五个 ssDNA 序列的光谱发现足够依赖于组成，因此无需任何先进的多元数据分析技术即可对其进行区分。
