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给出了3.3′二乙基硫醛三碳菁化碘(DTTC)分子的自然拉曼光谱、表面增强拉曼光谱(SERS)、以及理论计算拉曼光谱。SERS谱的增强基底是直径60 nm的金球和50 nm长的金棒,外包附一层硫基聚乙二醇(thiol-polyethylene glycol,简称Mpeg-SH)做为稳定层。同时,采用密度泛函(DFT)方法计算了DTTC分子的拉曼光谱,计算基于B3LYP/6-31G基组。经过仔细对比,计算光谱和两种实测光谱特征峰位有很好的一致性。对于不一致的部分,分析原因可能是由于金纳米粒子表面等离子体波对于不同的峰位,其增强程度不同所引起的。这项工作将有利于基于DTTC分子的红外波段拉曼光谱技术在生化领域的应用。
The natural Raman spectra, surface-enhanced Raman spectroscopy (SERS), and theoretically calculated Raman spectra of 3.3 ’diethylcarbamyldithiocarbocyanine iodide (DTTC) molecules are given. The SERS spectrum is based on a gold sphere with a diameter of 60 nm and a gold rod of 50 nm in length. A thiol-polyethylene glycol (Mpeg-SH) film is covered by the SERS spectrum as a stabilizing layer. At the same time, the Raman spectra of DTTC molecules were calculated by density functional theory (DFT) method and calculated based on B3LYP / 6-31G basis set. After careful comparison, there is good agreement between the calculated spectra and the two measured spectral characteristic peaks. For the inconsistent part, the reason for the analysis may be due to the surface plasmon waves of gold nanoparticles for different peak positions, the degree of enhancement caused by different. This work will be beneficial to the application of DTTC-based infrared Raman spectroscopy in biochemical applications.