Takemura Seiya, Watanabe Hikaru, Nishihara Tatsuya, Okamoto Akimitsu, Tanabe Kazuhito
Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University 5-10-1 Fuchinobe, Chuo-ku Sagamihara 252-5258 Japan
Research Center for Advanced Science and Technology, The University of Tokyo 4-6-1 Komaba, Meguro-ku Tokyo 153-8904 Japan.
RSC Adv. 2020 Oct 1;10(59):36119-36123. doi: 10.1039/d0ra06329k. eCollection 2020 Sep 28.
We propose to monitor molecular vibrations to identify metal ion-ligand complexation by means of Raman spectroscopy, which has been applied to track vibrational modes of molecules and to obtain a structural fingerprint. We prepared ligand molecules for Zn ion complexation with a dipycolylaminoethyl aniline (DPEA) skeleton and phenylacetylene unit as the Raman tag which showed a typical band around 2200 cm. Among the labeled ligands synthesized in this study, A-DPEA showed a strong band attributed to the acetylene unit at 2212 cm, while the addition of Zn ion resulted in a band shift to 2220 cm due to complex formation. The addition of other metal ions and titration experiments showed that A-DPEA bound with Zn selectively with a dissociation constant ( ) that was estimated to be 0.22 μM. We also conducted cellular experiments and found that complexation between A-DPEA and Zn also occurred in cells, with a shift in the Raman signal of the ligand from 2212 to 2215 cm. Thus, complex formation of the metal ion was identified by monitoring the Raman band shift.
我们建议通过拉曼光谱监测分子振动来识别金属离子-配体络合，拉曼光谱已被用于追踪分子的振动模式并获得结构指纹。我们制备了用于与锌离子络合的配体分子，其具有二吡啶基氨基乙基苯胺（DPEA）骨架和作为拉曼标签的苯乙炔单元，该单元在2200 cm附近显示出典型谱带。在本研究合成的标记配体中，A-DPEA在2212 cm处显示出归因于乙炔单元的强谱带，而加入锌离子后，由于络合物形成，谱带移至2220 cm。加入其他金属离子和滴定实验表明，A-DPEA与锌选择性结合，其解离常数（）估计为0.22 μM。我们还进行了细胞实验，发现A-DPEA与锌在细胞中也发生络合，配体的拉曼信号从2212 cm移至2215 cm。因此，通过监测拉曼谱带位移识别了金属离子的络合物形成。
