Surface-enhanced Raman scattering and DFT calculations studies of 3,3′-diethylthiatri- carbocyanine iodide
Article first published online: 1 APR 2011
Copyright © 2011 John Wiley & Sons, Ltd.
Journal of Raman Spectroscopy
Volume 42, Issue 9, pages 1722–1727, September 2011
How to Cite
Cai, H., Zhu, J., Chen, G., Liu, L., He, G. S. and Zhang, X. (2011), Surface-enhanced Raman scattering and DFT calculations studies of 3,3′-diethylthiatri- carbocyanine iodide. J. Raman Spectrosc., 42: 1722–1727. doi: 10.1002/jrs.2929
- Issue published online: 19 SEP 2011
- Article first published online: 1 APR 2011
- Manuscript Accepted: 25 JAN 2011
- Manuscript Received: 2 MAY 2010
- NCI. Grant Number: RO1CA119397
- NIH. Grant Number: CA104492
- DFT calculations;
- band assignments;
As an infrared Raman probe, the molecule 3,3′-diethylthiatricarbocyanine iodide (DTTC) has received much attention in the past decades due to its potential applications in Raman imaging, single-cell detection, cancer diagnosis, and surface-enhanced Raman scattering (SERS). In this work, ordinary Raman, SERS, and theoretical Raman spectra were investigated to estimate the DTTC suspension. More specifically, the original gold nanospheres (60 nm diameter) and gold nanorods were encoded with DTTC and stabilized with a layer of thiol–polyethylene glycol as Raman reporter; SERS data were also obtained from the samples. Hartree–Fock theory and density functional theory (DFT) calculation were applied to calculate the optimized Raman spectra of DTTC in water on the B3LYP/6-31G level. Subsequently, the obtained experimental spectra from DTTC were carefully compared with the theoretically calculated spectra, and good agreement was obtained between the theoretical and experimental results.The bands between 500 and 3100 cm−1 in the ordinary Raman and SERS spectra were assigned as well. This work will facilitate the development of ultrasensitive SERS probes for advanced biomedical imaging applications. Copyright © 2011 John Wiley & Sons, Ltd.