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.

3.3′-diethylthiatricarbocyanine iodide (DTTC) dye is an important infrared Raman probe molecule, and has received great attention in the past decades due to their potential applications in Raman imaging, single cell detection, and tumor marker. In the present work, ordinary Raman, surface enhanced Raman scattering (SERS), and theoretical Raman spectra were given to estimate the Raman spectrum of DTTC suspension. More specifically, the original gold nanospheres (60-nm diameter) and gold nanorods (NRs) were encoded with DTTC and stabilized with a layer of thiol-polyethylene glycol (PEG) as Raman reporter, and SERS data were obtained from the samples. Density functional theory (DFT) calculation was applied to calculate the optimized Raman spectra of DTTC water solvent on a B3LYP/6-31G level. Subsequently, the obtained experimental spectra from the DTTC were carefully compared with the theoretically calculated spectra. From the spectra comparation, good agreements were obtained between the theoretical and experimental results. This work will facilitate the development of ultrasensitive SERS probes for advanced biomedical applications.