Abstract
One of the most intriguing findings in single molecule spectroscopy (SMS) is the observation of Raman spectra of individual molecules, despite the small cross section of the transitions involved. The observation of the spectra can be explained by the surface enhanced Raman scattering (SERRS) effect. At the single-molecule level, the SERRS-spectra recorded as a function of time reveal inhomogeneous behaviour such as on/off blinking, spectral diffusion, intensity fluctuations of vibrational line, and even splitting of some lines within the spectrum of one molecule. Single-molecule SERRS (SM-SERRS) spectroscopy opens up exciting opportunities in the field of biophysics and biomedical spectroscopy. The first example of single protein SERRS was performed on hemoglobin. However, the possibility of extracting the heme group by silver sols can not be excluded. Here we report on SM-SERRS spectra of enhanced green fluorescent protein (EGFP) in which the chromophore is kept in the protein. The time series of SM-SERRS spectra suggest the conversion of the EGFP chromophore between the deprotonated and the protonated form. Autocorrelation analysis of SM-SERRS trajectory reveals the presence of fast dynamics taking place in the protein. Our findings show the potential of the technique to study structural dynamics of protein molecules.
Original language | English (US) |
---|---|
Pages (from-to) | 79-87 |
Number of pages | 9 |
Journal | Proceedings of SPIE - The International Society for Optical Engineering |
Volume | 5329 |
DOIs | |
State | Published - 2004 |
Externally published | Yes |
Event | Genetically Engineered and Optical Probes for Biomedical Applications II - San Jose, CA, United States Duration: Jan 24 2004 → Jan 27 2004 |
Keywords
- Enhanced green fluorescent protein (EGFP)
- Single molecule
- Surface enhanced resonance raman scattering (SERRS)
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Applied Mathematics
- Electrical and Electronic Engineering
- Computer Science Applications