Monitoring of local pH in photodynamic therapy-treated live cancer cells using surface-enhanced Raman scattering probes
Article first published online: 28 JAN 2011
Copyright © 2011 John Wiley & Sons, Ltd.
Journal of Raman Spectroscopy
Volume 42, Issue 6, pages 1215–1221, June 2011
How to Cite
Bálint, Š., Rao, S., Marro, M., Miškovský, P. and Petrov, D. (2011), Monitoring of local pH in photodynamic therapy-treated live cancer cells using surface-enhanced Raman scattering probes. J. Raman Spectrosc., 42: 1215–1221. doi: 10.1002/jrs.2856
- Issue published online: 17 JUN 2011
- Article first published online: 28 JAN 2011
- Manuscript Accepted: 25 OCT 2010
- Manuscript Received: 8 SEP 2010
- surface-enhanced Raman scattering;
- live cell;
- pH monitoring;
- drug diffusion
The local pH inside individual live glioma (U-87 MG) cancer cells was monitored after treatment by the photodynamic therapy drug 6-methyl-1,3,8-trihydroxyanthraquinone (emodin). The cellular pH is tracked by the real-time measurement of the surface-enhanced Raman scattering (SERS) from a probe that is embedded in the cell. The probe is a micrometer-sized silica bead that is covered by nanosized silver colloids, which enhance Raman signal, and 4-mercaptobenzoic acid (pMBA) whose molecular vibrations and resulting Raman spectrum are sensitive to pH. Visible excitation at different light dosages is used to activate the drug. The results indicate cell maintenance of internal pH and cell death at low and high light dosage, respectively. We demonstrate that these SERS probes are an effective tool for ex vivo pH monitoring in a live cell thanks to their high optical sensitivity and noninvasive usage. Copyright © 2011 John Wiley & Sons, Ltd.