Mochizuki Masahito, Sato Shinichi, Asatyas Syifa, Leśnikowski Zbigniew J, Hayashi Tomohiro, Nakamura Hiroyuki
School of Materials and Chemical Technology, Tokyo Institute of Technology 4259 Nagatsuta-cho, Midori-ku Yokohama 226-8502 Japan
Laboratory of Chemical and Life Science Innovative Research, Tokyo Institute of Technology 4259 Nagatsuta-cho, Midori-ku Yokohama 226-8502 Japan
RSC Adv. 2019 Aug 2;9(41):23973-23978. doi: 10.1039/c9ra04228h. eCollection 2019 Jul 29.
Raman spectroscopic measurements and theoretical calculation revealed that the Raman bands corresponding to the B-H stretching vibrations of two types of simple icosahedral boron clusters, -carborane 3 and -dodecaborate 4 appeared at approximately 2450-2700 cm, and did not overlap with those of cellular components. Although -carborane 3 possesses a possible property as a Raman probe, it was difficult to measure Raman imaging in the cell due to its poor water solubility. In fact, -carborane derivative 6, which internally has an alkyne moiety, exhibited very weak Raman signals of the C[triple bond, length as m-dash]C stretching and the B-H stretching vibrations were barely detected at a 400 ppm boron concentration in HeLa cells. In contrast, -dodecaborate derivatives such as BSH (5) were found to be a potential Raman imaging probe cluster for target molecules in the cell. BSH-conjugated cholesterol 7 (BSH-Chol) was synthesized and used in Raman imaging in cells. Raman imaging and spectral analysis revealed that BSH-based Raman tags provide a versatile platform for quantitative Raman imaging.
拉曼光谱测量和理论计算表明，两种类型的简单二十面体硼簇（碳硼烷3和十二硼酸盐4）中与B-H伸缩振动相对应的拉曼带出现在约2450 - 2700 cm处，且不与细胞成分的拉曼带重叠。尽管碳硼烷3具有作为拉曼探针的潜在特性，但由于其水溶性差，难以在细胞中测量拉曼成像。实际上，内部含有炔基部分的碳硼烷衍生物6在HeLa细胞中400 ppm硼浓度下，C≡C伸缩振动的拉曼信号非常弱，且几乎检测不到B-H伸缩振动。相比之下，十二硼酸盐衍生物如BSH（5）被发现是细胞中目标分子的潜在拉曼成像探针簇。合成了BSH共轭胆固醇7（BSH-Chol）并用于细胞的拉曼成像。拉曼成像和光谱分析表明，基于BSH的拉曼标签为定量拉曼成像提供了一个通用平台。
