几种核酸碱基的针尖增强拉曼光谱研究

Tip-enhanced Raman spectroscopy of several nucleoacids

核酸碱基的针尖增强拉曼光谱表征对RNA或DNA中碱基的高空间分辨光谱研究具有重要价值。在本研究中,首先使用第一性原理,对腺嘌呤、胞嘧啶、鸟嘌呤和胸腺嘧啶的拉曼振动模式进行了计算。远场拉曼测试结果表明,这四种核酸碱基的远场拉曼峰位与计算结果吻合很好。成功地获得了这四种核酸碱基的针尖增强拉曼光谱(TERS),研究结果表明,不同位点处核酸碱基的针尖增强拉曼光谱中峰位和峰强虽然有较大变化,但是测试得到的TERS峰位都是计算峰位数据集合的某个子集。

Tip-enhanced Raman spectroscopy(TERS)of nucleobase plays important role for the high-spatial resolution spectroscopy study of nucleobases of RNA or DNA.In this paper,first principle calculation method was employed at first to calculate the Raman vibration modes of adenine,cytosine,guanine and thymine.Far-field Raman spectroscopy measurements indicate the far field Raman peak positions are in good agreement with the theoretical expectations.Then,we successfully conducted TERS measurements on these four nucleoacids.The obtained results show that the peak positions and intensities of TERS spectra of adenine,cytosine,guanine and thymine at different positions have great changes.However,the TERS peak positions measured at a position is the subset of the calculated peak positions.